TTY/serial driver patches for 3.2

index 93e05d1..5354ae9 100644
@@ -54,6 +54,7 @@ extern void __init udbg_init_40x_realmode(void);
 extern void __init udbg_init_cpm(void);
 extern void __init udbg_init_usbgecko(void);
 extern void __init udbg_init_wsp(void);
+extern void __init udbg_init_ehv_bc(void);
 
 #endif /* __KERNEL__ */
 #endif /* _ASM_POWERPC_UDBG_H */

index faa82c1..b4607a9 100644
@@ -67,6 +67,8 @@ void __init udbg_early_init(void)
 	udbg_init_usbgecko();
 #elif defined(CONFIG_PPC_EARLY_DEBUG_WSP)
 	udbg_init_wsp();
+#elif defined(CONFIG_PPC_EARLY_DEBUG_EHV_BC)
+	udbg_init_ehv_bc();
 #endif
 
 #ifdef CONFIG_PPC_EARLY_DEBUG

888 lines not on this page · raw message

index 272e417..e67fb20 100644
@@ -2124,7 +2124,6 @@ static int mgsl_write(struct tty_struct * tty,
 	if ( info->params.mode == MGSL_MODE_HDLC ||
 			info->params.mode == MGSL_MODE_RAW ) {
 		/* operating in synchronous (frame oriented) mode */
-		/* operating in synchronous (frame oriented) mode */
 		if (info->tx_active) {
 
 			if ( info->params.mode == MGSL_MODE_HDLC ) {

index db7912c..2cbf1bd 100644
@@ -57,7 +57,7 @@ static struct lock_class_key port_lock_key;
 
 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
 					struct ktermios *old_termios);
-static void __uart_wait_until_sent(struct uart_port *port, int timeout);
+static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
 static void uart_change_pm(struct uart_state *state, int pm_state);
 
 /*

@@ -1304,16 +1304,8 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 	tty->closing = 1;
 	spin_unlock_irqrestore(&port->lock, flags);
 
-	if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) {
-		/*
-		 * hack: open-coded tty_wait_until_sent to avoid
-		 * recursive tty_lock
-		 */
-		long timeout = msecs_to_jiffies(port->closing_wait);
-		if (wait_event_interruptible_timeout(tty->write_wait,
-				!tty_chars_in_buffer(tty), timeout) >= 0)
-			__uart_wait_until_sent(uport, timeout);
-	}
+	if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
+		tty_wait_until_sent(tty, msecs_to_jiffies(port->closing_wait));
 
 	/*
 	 * At this point, we stop accepting input.  To do this, we

@@ -1329,7 +1321,7 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 		 * has completely drained; this is especially
 		 * important if there is a transmit FIFO!
 		 */
-		__uart_wait_until_sent(uport, uport->timeout);
+		uart_wait_until_sent(tty, uport->timeout);
 	}
 
 	uart_shutdown(tty, state);

@@ -1363,8 +1355,10 @@ done:
 	mutex_unlock(&port->mutex);
 }
 
-static void __uart_wait_until_sent(struct uart_port *port, int timeout)
+static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
 {
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->uart_port;
 	unsigned long char_time, expire;
 
 	if (port->type == PORT_UNKNOWN || port->fifosize == 0)

@@ -1416,16 +1410,6 @@ static void __uart_wait_until_sent(struct uart_port *port, int timeout)
 	}
 }
 
-static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
-{
-	struct uart_state *state = tty->driver_data;
-	struct uart_port *port = state->uart_port;
-
-	tty_lock();
-	__uart_wait_until_sent(port, timeout);
-	tty_unlock();
-}
-
 /*
  * This is called with the BKL held in
  *  linux/drivers/char/tty_io.c:do_tty_hangup()

index e6ba838..29cbfd8 100644
@@ -804,8 +804,6 @@ static int __init msm_console_setup(struct console *co, char *options)
 	if (unlikely(!port->membase))
 		return -ENXIO;
 
-	port->cons = co;
-
 	msm_init_clock(port);
 
 	if (options)

index 2cbf1bd..4786232 100644
@@ -72,7 +72,7 @@ void uart_write_wakeup(struct uart_port *port)
 	 * closed.  No cookie for you.
 	 */
 	BUG_ON(!state);
-	tasklet_schedule(&state->tlet);
+	tty_wakeup(state->port.tty);
 }
 
 static void uart_stop(struct tty_struct *tty)

@@ -107,12 +107,6 @@ static void uart_start(struct tty_struct *tty)
 	spin_unlock_irqrestore(&port->lock, flags);
 }
 
-static void uart_tasklet_action(unsigned long data)
-{
-	struct uart_state *state = (struct uart_state *)data;
-	tty_wakeup(state->port.tty);
-}
-
 static inline void
 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
 {

@@ -250,11 +244,6 @@ static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
 	}
 
 	/*
-	 * kill off our tasklet
-	 */
-	tasklet_kill(&state->tlet);
-
-	/*
 	 * Free the transmit buffer page.
 	 */
 	if (state->xmit.buf) {

@@ -2277,8 +2266,6 @@ int uart_register_driver(struct uart_driver *drv)
 		port->ops = &uart_port_ops;
 		port->close_delay     = 500;	/* .5 seconds */
 		port->closing_wait    = 30000;	/* 30 seconds */
-		tasklet_init(&state->tlet, uart_tasklet_action,
-			     (unsigned long)state);
 	}
 
 	retval = tty_register_driver(normal);

@@ -2439,11 +2426,6 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
 	 */
 	uport->type = PORT_UNKNOWN;
 
-	/*
-	 * Kill the tasklet, and free resources.
-	 */
-	tasklet_kill(&state->tlet);
-
 	state->uart_port = NULL;
 	mutex_unlock(&port_mutex);
 

index a5c3114..76e1103 100644
@@ -384,7 +384,6 @@ struct uart_state {
 	int			pm_state;
 	struct circ_buf		xmit;
 
-	struct tasklet_struct	tlet;
 	struct uart_port	*uart_port;
 };
 

index 2205795..6d43f55 100644
@@ -1529,7 +1529,6 @@ static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
 {
 	struct async_struct * info = tty->driver_data;
 	unsigned long orig_jiffies, char_time;
-	int tty_was_locked = tty_locked();
 	int lsr;
 
 	if (serial_paranoia_check(info, tty->name, "rs_wait_until_sent"))

@@ -1541,12 +1540,6 @@ static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
 	orig_jiffies = jiffies;
 
 	/*
-	 * tty_wait_until_sent is called from lots of places,
-	 * with or without the BTM.
-	 */
-	if (!tty_was_locked)
-		tty_lock();
-	/*
 	 * Set the check interval to be 1/5 of the estimated time to
 	 * send a single character, and make it at least 1.  The check
 	 * interval should also be less than the timeout.

@@ -1586,8 +1579,7 @@ static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
 			break;
 	}
 	__set_current_state(TASK_RUNNING);
-	if (!tty_was_locked)
-		tty_unlock();
+
 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
 	printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
 #endif

index 4786232..44c2963 100644
@@ -1245,8 +1245,6 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 	struct uart_port *uport;
 	unsigned long flags;
 
-	BUG_ON(!tty_locked());
-
 	if (!state)
 		return;
 

@@ -1411,7 +1409,6 @@ static void uart_hangup(struct tty_struct *tty)
 	struct tty_port *port = &state->port;
 	unsigned long flags;
 
-	BUG_ON(!tty_locked());
 	pr_debug("uart_hangup(%d)\n", state->uart_port->line);
 
 	mutex_lock(&port->mutex);

@@ -1498,7 +1495,6 @@ static int uart_open(struct tty_struct *tty, struct file *filp)
 	struct tty_port *port;
 	int retval, line = tty->index;
 
-	BUG_ON(!tty_locked());
 	pr_debug("uart_open(%d) called\n", line);
 
 	/*

index ef925d5..512c49f 100644
@@ -450,7 +450,6 @@ static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)
 	if (ld->ops->open) {
 		int ret;
                 /* BTM here locks versus a hangup event */
-		WARN_ON(!tty_locked());
 		ret = ld->ops->open(tty);
 		if (ret)
 			clear_bit(TTY_LDISC_OPEN, &tty->flags);

index 3b2bb77..9ff986c 100644
@@ -15,30 +15,18 @@
  * Don't use in new code.
  */
 static DEFINE_MUTEX(big_tty_mutex);
-struct task_struct *__big_tty_mutex_owner;
-EXPORT_SYMBOL_GPL(__big_tty_mutex_owner);
 
 /*
  * Getting the big tty mutex.
  */
 void __lockfunc tty_lock(void)
 {
-	struct task_struct *task = current;
-
-	WARN_ON(__big_tty_mutex_owner == task);
-
 	mutex_lock(&big_tty_mutex);
-	__big_tty_mutex_owner = task;
 }
 EXPORT_SYMBOL(tty_lock);
 
 void __lockfunc tty_unlock(void)
 {
-	struct task_struct *task = current;
-
-	WARN_ON(__big_tty_mutex_owner != task);
-	__big_tty_mutex_owner = NULL;
-
 	mutex_unlock(&big_tty_mutex);
 }
 EXPORT_SYMBOL(tty_unlock);

index fb864e7..7a0a12a 100644
@@ -301,6 +301,8 @@ int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *t
 /* Insert the contents of the selection buffer into the
  * queue of the tty associated with the current console.
  * Invoked by ioctl().
+ *
+ * Locking: always called with BTM from vt_ioctl
  */
 int paste_selection(struct tty_struct *tty)
 {

@@ -310,8 +312,6 @@ int paste_selection(struct tty_struct *tty)
 	struct  tty_ldisc *ld;
 	DECLARE_WAITQUEUE(wait, current);
 
-	/* always called with BTM from vt_ioctl */
-	WARN_ON(!tty_locked());
 
 	console_lock();
 	poke_blanked_console();

index 44bc0c5..6d5eceb 100644
@@ -600,8 +600,6 @@ extern long vt_compat_ioctl(struct tty_struct *tty,
 /* functions for preparation of BKL removal */
 extern void __lockfunc tty_lock(void) __acquires(tty_lock);
 extern void __lockfunc tty_unlock(void) __releases(tty_lock);
-extern struct task_struct *__big_tty_mutex_owner;
-#define tty_locked()		(current == __big_tty_mutex_owner)
 
 /*
  * wait_event_interruptible_tty -- wait for a condition with the tty lock held

index c0e8f2e..5beef49 100644
@@ -45,7 +45,6 @@
 #undef	CY_DEBUG_IO
 #undef	CY_DEBUG_COUNT
 #undef	CY_DEBUG_DTR
-#undef	CY_DEBUG_WAIT_UNTIL_SENT
 #undef	CY_DEBUG_INTERRUPTS
 #undef	CY_16Y_HACK
 #undef	CY_ENABLE_MONITORING

@@ -1678,16 +1677,10 @@ static void cy_wait_until_sent(struct tty_struct *tty, int timeout)
 	 */
 	if (!timeout || timeout > 2 * info->timeout)
 		timeout = 2 * info->timeout;
-#ifdef CY_DEBUG_WAIT_UNTIL_SENT
-	printk(KERN_DEBUG "In cy_wait_until_sent(%d) check=%d, jiff=%lu...",
-		timeout, char_time, jiffies);
-#endif
+
 	card = info->card;
 	if (!cy_is_Z(card)) {
 		while (cyy_readb(info, CySRER) & CyTxRdy) {
-#ifdef CY_DEBUG_WAIT_UNTIL_SENT
-			printk(KERN_DEBUG "Not clean (jiff=%lu)...", jiffies);
-#endif
 			if (msleep_interruptible(jiffies_to_msecs(char_time)))
 				break;
 			if (timeout && time_after(jiffies, orig_jiffies +

@@ -1697,9 +1690,6 @@ static void cy_wait_until_sent(struct tty_struct *tty, int timeout)
 	}
 	/* Run one more char cycle */
 	msleep_interruptible(jiffies_to_msecs(char_time * 5));
-#ifdef CY_DEBUG_WAIT_UNTIL_SENT
-	printk(KERN_DEBUG "Clean (jiff=%lu)...done\n", jiffies);
-#endif
 }
 
 static void cy_flush_buffer(struct tty_struct *tty)

index 7fc8c02..8998d52 100644
@@ -2005,16 +2005,9 @@ static void mxser_wait_until_sent(struct tty_struct *tty, int timeout)
 	 */
 	if (!timeout || timeout > 2 * info->timeout)
 		timeout = 2 * info->timeout;
-#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
-	printk(KERN_DEBUG "In rs_wait_until_sent(%d) check=%lu...",
-		timeout, char_time);
-	printk("jiff=%lu...", jiffies);
-#endif
+
 	spin_lock_irqsave(&info->slock, flags);
 	while (!((lsr = inb(info->ioaddr + UART_LSR)) & UART_LSR_TEMT)) {
-#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
-		printk("lsr = %d (jiff=%lu)...", lsr, jiffies);
-#endif
 		spin_unlock_irqrestore(&info->slock, flags);
 		schedule_timeout_interruptible(char_time);
 		spin_lock_irqsave(&info->slock, flags);

@@ -2025,10 +2018,6 @@ static void mxser_wait_until_sent(struct tty_struct *tty, int timeout)
 	}
 	spin_unlock_irqrestore(&info->slock, flags);
 	set_current_state(TASK_RUNNING);
-
-#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
-	printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
-#endif
 }
 
 /*

index ff69791..e08bc04 100644
@@ -234,8 +234,8 @@ static void bfin_serial_rx_chars(struct bfin_serial_port *uart)
 	status = UART_GET_LSR(uart);
 	UART_CLEAR_LSR(uart);
 
- 	ch = UART_GET_CHAR(uart);
- 	uart->port.icount.rx++;
+	ch = UART_GET_CHAR(uart);
+	uart->port.icount.rx++;
 
 #if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
 	defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)

@@ -739,9 +739,8 @@ static int bfin_serial_startup(struct uart_port *port)
 			pr_info("Unable to attach BlackFin UART CTS interrupt. So, disable it.\n");
 		}
 	}
-	if (uart->rts_pin >= 0) {
+	if (uart->rts_pin >= 0)
 		gpio_direction_output(uart->rts_pin, 0);
-	}
 #endif
 #ifdef CONFIG_SERIAL_BFIN_HARD_CTSRTS
 	if (uart->cts_pin >= 0 && request_irq(uart->status_irq,

@@ -1091,10 +1090,18 @@ bfin_serial_console_get_options(struct bfin_serial_port *uart, int *baud,
 				*parity = 'o';
 		}
 		switch (lcr & 0x03) {
-			case 0:	*bits = 5; break;
-			case 1:	*bits = 6; break;
-			case 2:	*bits = 7; break;
-			case 3:	*bits = 8; break;
+		case 0:
+			*bits = 5;
+			break;
+		case 1:
+			*bits = 6;
+			break;
+		case 2:
+			*bits = 7;
+			break;
+		case 3:
+			*bits = 8;
+			break;
 		}
 		/* Set DLAB in LCR to Access DLL and DLH */
 		UART_SET_DLAB(uart);

@@ -1183,7 +1190,7 @@ static struct console bfin_serial_console = {
 	.index		= -1,
 	.data		= &bfin_serial_reg,
 };
-#define BFIN_SERIAL_CONSOLE	&bfin_serial_console
+#define BFIN_SERIAL_CONSOLE	(&bfin_serial_console)
 #else
 #define BFIN_SERIAL_CONSOLE	NULL
 #endif /* CONFIG_SERIAL_BFIN_CONSOLE */

similarity index 100%
rename from drivers/tty/serial/bfin_5xx.c
rename to drivers/tty/serial/bfin_uart.c

index b3915b7..e716839 100644
@@ -259,7 +259,7 @@ EXPORT_SYMBOL_GPL(unregister_vt_notifier);
 
 static void notify_write(struct vc_data *vc, unsigned int unicode)
 {
-	struct vt_notifier_param param = { .vc = vc, unicode = unicode };
+	struct vt_notifier_param param = { .vc = vc, .c = unicode };
 	atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
 }
 

index e08bc04..c7e592d 100644
@@ -667,17 +667,17 @@ static int bfin_serial_startup(struct uart_port *port)
 		kgdboc_break_enabled = 0;
 	else {
 # endif
-	if (request_irq(uart->port.irq, bfin_serial_rx_int, IRQF_DISABLED,
+	if (request_irq(uart->rx_irq, bfin_serial_rx_int, IRQF_DISABLED,
 	     "BFIN_UART_RX", uart)) {
 		printk(KERN_NOTICE "Unable to attach BlackFin UART RX interrupt\n");
 		return -EBUSY;
 	}
 
 	if (request_irq
-	    (uart->port.irq+1, bfin_serial_tx_int, IRQF_DISABLED,
+	    (uart->tx_irq, bfin_serial_tx_int, IRQF_DISABLED,
 	     "BFIN_UART_TX", uart)) {
 		printk(KERN_NOTICE "Unable to attach BlackFin UART TX interrupt\n");
-		free_irq(uart->port.irq, uart);
+		free_irq(uart->rx_irq, uart);
 		return -EBUSY;
 	}
 

@@ -692,7 +692,7 @@ static int bfin_serial_startup(struct uart_port *port)
 		 */
 		unsigned uart_dma_ch_rx, uart_dma_ch_tx;
 
-		switch (uart->port.irq) {
+		switch (uart->rx_irq) {
 		case IRQ_UART3_RX:
 			uart_dma_ch_rx = CH_UART3_RX;
 			uart_dma_ch_tx = CH_UART3_TX;

@@ -709,16 +709,16 @@ static int bfin_serial_startup(struct uart_port *port)
 		if (uart_dma_ch_rx &&
 			request_dma(uart_dma_ch_rx, "BFIN_UART_RX") < 0) {
 			printk(KERN_NOTICE"Fail to attach UART interrupt\n");
-			free_irq(uart->port.irq, uart);
-			free_irq(uart->port.irq + 1, uart);
+			free_irq(uart->rx_irq, uart);
+			free_irq(uart->tx_irq, uart);
 			return -EBUSY;
 		}
 		if (uart_dma_ch_tx &&
 			request_dma(uart_dma_ch_tx, "BFIN_UART_TX") < 0) {
 			printk(KERN_NOTICE "Fail to attach UART interrupt\n");
 			free_dma(uart_dma_ch_rx);
-			free_irq(uart->port.irq, uart);
-			free_irq(uart->port.irq + 1, uart);
+			free_irq(uart->rx_irq, uart);
+			free_irq(uart->tx_irq, uart);
 			return -EBUSY;
 		}
 	}

@@ -785,8 +785,8 @@ static void bfin_serial_shutdown(struct uart_port *port)
 		break;
 	};
 #endif
-	free_irq(uart->port.irq, uart);
-	free_irq(uart->port.irq+1, uart);
+	free_irq(uart->rx_irq, uart);
+	free_irq(uart->tx_irq, uart);
 #endif
 
 #ifdef CONFIG_SERIAL_BFIN_CTSRTS

@@ -1319,14 +1319,22 @@ static int bfin_serial_probe(struct platform_device *pdev)
 		}
 		uart->port.mapbase = res->start;
 
-		uart->port.irq = platform_get_irq(pdev, 0);
-		if (uart->port.irq < 0) {
-			dev_err(&pdev->dev, "No uart RX/TX IRQ specified\n");
+		uart->tx_irq = platform_get_irq(pdev, 0);
+		if (uart->tx_irq < 0) {
+			dev_err(&pdev->dev, "No uart TX IRQ specified\n");
 			ret = -ENOENT;
 			goto out_error_unmap;
 		}
 
-		uart->status_irq = platform_get_irq(pdev, 1);
+		uart->rx_irq = platform_get_irq(pdev, 1);
+		if (uart->rx_irq < 0) {
+			dev_err(&pdev->dev, "No uart RX IRQ specified\n");
+			ret = -ENOENT;
+			goto out_error_unmap;
+		}
+		uart->port.irq = uart->rx_irq;
+
+		uart->status_irq = platform_get_irq(pdev, 2);
 		if (uart->status_irq < 0) {
 			dev_err(&pdev->dev, "No uart status IRQ specified\n");
 			ret = -ENOENT;

index afc6294..9b84654 100644
@@ -83,6 +83,16 @@ static int s3c24xx_serial_txempty_nofifo(struct uart_port *port)
 	return (rd_regl(port, S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE);
 }
 
+/*
+ * s3c64xx and later SoC's include the interrupt mask and status registers in
+ * the controller itself, unlike the s3c24xx SoC's which have these registers
+ * in the interrupt controller. Check if the port type is s3c64xx or higher.
+ */
+static int s3c24xx_serial_has_interrupt_mask(struct uart_port *port)
+{
+	return to_ourport(port)->info->type == PORT_S3C6400;
+}
+
 static void s3c24xx_serial_rx_enable(struct uart_port *port)
 {
 	unsigned long flags;

@@ -126,7 +136,11 @@ static void s3c24xx_serial_stop_tx(struct uart_port *port)
 	struct s3c24xx_uart_port *ourport = to_ourport(port);
 
 	if (tx_enabled(port)) {
-		disable_irq_nosync(ourport->tx_irq);
+		if (s3c24xx_serial_has_interrupt_mask(port))
+			__set_bit(S3C64XX_UINTM_TXD,
+				portaddrl(port, S3C64XX_UINTM));
+		else
+			disable_irq_nosync(ourport->tx_irq);
 		tx_enabled(port) = 0;
 		if (port->flags & UPF_CONS_FLOW)
 			s3c24xx_serial_rx_enable(port);

@@ -141,19 +155,26 @@ static void s3c24xx_serial_start_tx(struct uart_port *port)
 		if (port->flags & UPF_CONS_FLOW)
 			s3c24xx_serial_rx_disable(port);
 
-		enable_irq(ourport->tx_irq);
+		if (s3c24xx_serial_has_interrupt_mask(port))
+			__clear_bit(S3C64XX_UINTM_TXD,
+				portaddrl(port, S3C64XX_UINTM));
+		else
+			enable_irq(ourport->tx_irq);
 		tx_enabled(port) = 1;
 	}
 }
 
-
 static void s3c24xx_serial_stop_rx(struct uart_port *port)
 {
 	struct s3c24xx_uart_port *ourport = to_ourport(port);
 
 	if (rx_enabled(port)) {
 		dbg("s3c24xx_serial_stop_rx: port=%p\n", port);
-		disable_irq_nosync(ourport->rx_irq);
+		if (s3c24xx_serial_has_interrupt_mask(port))
+			__set_bit(S3C64XX_UINTM_RXD,
+				portaddrl(port, S3C64XX_UINTM));
+		else
+			disable_irq_nosync(ourport->rx_irq);
 		rx_enabled(port) = 0;
 	}
 }

@@ -320,6 +341,28 @@ static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id)
 	return IRQ_HANDLED;
 }
 
+/* interrupt handler for s3c64xx and later SoC's.*/
+static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id)
+{
+	struct s3c24xx_uart_port *ourport = id;
+	struct uart_port *port = &ourport->port;
+	unsigned int pend = rd_regl(port, S3C64XX_UINTP);
+	unsigned long flags;
+	irqreturn_t ret = IRQ_HANDLED;
+
+	spin_lock_irqsave(&port->lock, flags);
+	if (pend & S3C64XX_UINTM_RXD_MSK) {
+		ret = s3c24xx_serial_rx_chars(irq, id);
+		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_RXD_MSK);
+	}
+	if (pend & S3C64XX_UINTM_TXD_MSK) {
+		ret = s3c24xx_serial_tx_chars(irq, id);
+		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_TXD_MSK);
+	}
+	spin_unlock_irqrestore(&port->lock, flags);
+	return ret;
+}
+
 static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
 {
 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);

@@ -377,18 +420,25 @@ static void s3c24xx_serial_shutdown(struct uart_port *port)
 	struct s3c24xx_uart_port *ourport = to_ourport(port);
 
 	if (ourport->tx_claimed) {
-		free_irq(ourport->tx_irq, ourport);
+		if (!s3c24xx_serial_has_interrupt_mask(port))
+			free_irq(ourport->tx_irq, ourport);
 		tx_enabled(port) = 0;
 		ourport->tx_claimed = 0;
 	}
 
 	if (ourport->rx_claimed) {
-		free_irq(ourport->rx_irq, ourport);
+		if (!s3c24xx_serial_has_interrupt_mask(port))
+			free_irq(ourport->rx_irq, ourport);
 		ourport->rx_claimed = 0;
 		rx_enabled(port) = 0;
 	}
-}
 
+	/* Clear pending interrupts and mask all interrupts */
+	if (s3c24xx_serial_has_interrupt_mask(port)) {
+		wr_regl(port, S3C64XX_UINTP, 0xf);
+		wr_regl(port, S3C64XX_UINTM, 0xf);
+	}
+}
 
 static int s3c24xx_serial_startup(struct uart_port *port)
 {

@@ -436,6 +486,33 @@ static int s3c24xx_serial_startup(struct uart_port *port)
 	return ret;
 }
 
+static int s3c64xx_serial_startup(struct uart_port *port)
+{
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+	int ret;
+
+	dbg("s3c64xx_serial_startup: port=%p (%08lx,%p)\n",
+	    port->mapbase, port->membase);
+
+	ret = request_irq(port->irq, s3c64xx_serial_handle_irq, IRQF_SHARED,
+			  s3c24xx_serial_portname(port), ourport);
+	if (ret) {
+		printk(KERN_ERR "cannot get irq %d\n", port->irq);
+		return ret;
+	}
+
+	/* For compatibility with s3c24xx Soc's */
+	rx_enabled(port) = 1;
+	ourport->rx_claimed = 1;
+	tx_enabled(port) = 0;
+	ourport->tx_claimed = 1;
+
+	/* Enable Rx Interrupt */
+	__clear_bit(S3C64XX_UINTM_RXD, portaddrl(port, S3C64XX_UINTM));
+	dbg("s3c64xx_serial_startup ok\n");
+	return ret;
+}
+
 /* power power management control */
 
 static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,

@@ -879,7 +956,6 @@ static struct uart_ops s3c24xx_serial_ops = {
 	.verify_port	= s3c24xx_serial_verify_port,
 };
 
-
 static struct uart_driver s3c24xx_uart_drv = {
 	.owner		= THIS_MODULE,
 	.driver_name	= "s3c2410_serial",

@@ -895,7 +971,6 @@ static struct s3c24xx_uart_port s3c24xx_serial_ports[CONFIG_SERIAL_SAMSUNG_UARTS
 		.port = {
 			.lock		= __SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[0].port.lock),
 			.iotype		= UPIO_MEM,
-			.irq		= IRQ_S3CUART_RX0,
 			.uartclk	= 0,
 			.fifosize	= 16,
 			.ops		= &s3c24xx_serial_ops,

@@ -907,7 +982,6 @@ static struct s3c24xx_uart_port s3c24xx_serial_ports[CONFIG_SERIAL_SAMSUNG_UARTS
 		.port = {
 			.lock		= __SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[1].port.lock),
 			.iotype		= UPIO_MEM,
-			.irq		= IRQ_S3CUART_RX1,
 			.uartclk	= 0,
 			.fifosize	= 16,
 			.ops		= &s3c24xx_serial_ops,

@@ -921,7 +995,6 @@ static struct s3c24xx_uart_port s3c24xx_serial_ports[CONFIG_SERIAL_SAMSUNG_UARTS
 		.port = {
 			.lock		= __SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[2].port.lock),
 			.iotype		= UPIO_MEM,
-			.irq		= IRQ_S3CUART_RX2,
 			.uartclk	= 0,
 			.fifosize	= 16,
 			.ops		= &s3c24xx_serial_ops,

@@ -935,7 +1008,6 @@ static struct s3c24xx_uart_port s3c24xx_serial_ports[CONFIG_SERIAL_SAMSUNG_UARTS
 		.port = {
 			.lock		= __SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[3].port.lock),
 			.iotype		= UPIO_MEM,
-			.irq		= IRQ_S3CUART_RX3,
 			.uartclk	= 0,
 			.fifosize	= 16,
 			.ops		= &s3c24xx_serial_ops,

@@ -1077,6 +1149,10 @@ static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
 	port->dev	= &platdev->dev;
 	ourport->info	= info;
 
+	/* Startup sequence is different for s3c64xx and higher SoC's */
+	if (s3c24xx_serial_has_interrupt_mask(port))
+		s3c24xx_serial_ops.startup = s3c64xx_serial_startup;
+
 	/* copy the info in from provided structure */
 	ourport->port.fifosize = info->fifosize;
 

@@ -1116,6 +1192,13 @@ static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
 
 	ourport->clk	= clk_get(&platdev->dev, "uart");
 
+	/* Keep all interrupts masked and cleared */
+	if (s3c24xx_serial_has_interrupt_mask(port)) {
+		wr_regl(port, S3C64XX_UINTM, 0xf);
+		wr_regl(port, S3C64XX_UINTP, 0xf);
+		wr_regl(port, S3C64XX_UINTSP, 0xf);
+	}
+
 	dbg("port: map=%08x, mem=%08x, irq=%d (%d,%d), clock=%ld\n",
 	    port->mapbase, port->membase, port->irq,
 	    ourport->rx_irq, ourport->tx_irq, port->uartclk);

index a69d9a5..8e87b78 100644
@@ -61,6 +61,7 @@ struct s3c24xx_uart_port {
 /* register access controls */
 
 #define portaddr(port, reg) ((port)->membase + (reg))
+#define portaddrl(port, reg) ((unsigned long *)((port)->membase + (reg)))
 
 #define rd_regb(port, reg) (__raw_readb(portaddr(port, reg)))
 #define rd_regl(port, reg) (__raw_readl(portaddr(port, reg)))

86 lines not on this page · raw message

index c026f67..443f85b 100644
@@ -27,36 +27,6 @@
 #define IRQ_VIC0_BASE	S3C_IRQ(0)
 #define IRQ_VIC1_BASE	S3C_IRQ(32)
 
-/* UART interrupts, each UART has 4 intterupts per channel so
- * use the space between the ISA and S3C main interrupts. Note, these
- * are not in the same order as the S3C24XX series! */
-
-#define IRQ_S3CUART_BASE0	(16)
-#define IRQ_S3CUART_BASE1	(20)
-#define IRQ_S3CUART_BASE2	(24)
-#define IRQ_S3CUART_BASE3	(28)
-
-#define UART_IRQ_RXD		(0)
-#define UART_IRQ_ERR		(1)
-#define UART_IRQ_TXD		(2)
-#define UART_IRQ_MODEM		(3)
-
-#define IRQ_S3CUART_RX0		(IRQ_S3CUART_BASE0 + UART_IRQ_RXD)
-#define IRQ_S3CUART_TX0		(IRQ_S3CUART_BASE0 + UART_IRQ_TXD)
-#define IRQ_S3CUART_ERR0	(IRQ_S3CUART_BASE0 + UART_IRQ_ERR)
-
-#define IRQ_S3CUART_RX1		(IRQ_S3CUART_BASE1 + UART_IRQ_RXD)
-#define IRQ_S3CUART_TX1		(IRQ_S3CUART_BASE1 + UART_IRQ_TXD)
-#define IRQ_S3CUART_ERR1	(IRQ_S3CUART_BASE1 + UART_IRQ_ERR)
-
-#define IRQ_S3CUART_RX2		(IRQ_S3CUART_BASE2 + UART_IRQ_RXD)
-#define IRQ_S3CUART_TX2		(IRQ_S3CUART_BASE2 + UART_IRQ_TXD)
-#define IRQ_S3CUART_ERR2	(IRQ_S3CUART_BASE2 + UART_IRQ_ERR)
-
-#define IRQ_S3CUART_RX3		(IRQ_S3CUART_BASE3 + UART_IRQ_RXD)
-#define IRQ_S3CUART_TX3		(IRQ_S3CUART_BASE3 + UART_IRQ_TXD)
-#define IRQ_S3CUART_ERR3	(IRQ_S3CUART_BASE3 + UART_IRQ_ERR)
-
 /* VIC based IRQs */
 
 #define S3C64XX_IRQ_VIC0(x)	(IRQ_VIC0_BASE + (x))

index 75d9a0e..b07357e 100644
@@ -25,29 +25,6 @@
 #include <plat/irq-uart.h>
 #include <plat/cpu.h>
 
-static struct s3c_uart_irq uart_irqs[] = {
-	[0] = {
-		.regs		= S3C_VA_UART0,
-		.base_irq	= IRQ_S3CUART_BASE0,
-		.parent_irq	= IRQ_UART0,
-	},
-	[1] = {
-		.regs		= S3C_VA_UART1,
-		.base_irq	= IRQ_S3CUART_BASE1,
-		.parent_irq	= IRQ_UART1,
-	},
-	[2] = {
-		.regs		= S3C_VA_UART2,
-		.base_irq	= IRQ_S3CUART_BASE2,
-		.parent_irq	= IRQ_UART2,
-	},
-	[3] = {
-		.regs		= S3C_VA_UART3,
-		.base_irq	= IRQ_S3CUART_BASE3,
-		.parent_irq	= IRQ_UART3,
-	},
-};
-
 /* setup the sources the vic should advertise resume for, even though it
  * is not doing the wake (set_irq_wake needs to be valid) */
 #define IRQ_VIC0_RESUME (1 << (IRQ_RTC_TIC - IRQ_VIC0_BASE))

@@ -67,6 +44,4 @@ void __init s3c64xx_init_irq(u32 vic0_valid, u32 vic1_valid)
 
 	/* add the timer sub-irqs */
 	s3c_init_vic_timer_irq(5, IRQ_TIMER0);
-
-	s3c_init_uart_irqs(uart_irqs, ARRAY_SIZE(uart_irqs));
 }

122 lines not on this page · raw message

index ba9121c..144dbfc 100644
@@ -37,41 +37,6 @@
 #define IRQ_VIC1_BASE		S5P_VIC1_BASE
 #define IRQ_VIC2_BASE		S5P_VIC2_BASE
 
-/* UART interrupts, each UART has 4 intterupts per channel so
- * use the space between the ISA and S3C main interrupts. Note, these
- * are not in the same order as the S3C24XX series! */
-
-#define IRQ_S5P_UART_BASE0	(16)
-#define IRQ_S5P_UART_BASE1	(20)
-#define IRQ_S5P_UART_BASE2	(24)
-#define IRQ_S5P_UART_BASE3	(28)
-
-#define UART_IRQ_RXD		(0)
-#define UART_IRQ_ERR		(1)
-#define UART_IRQ_TXD		(2)
-
-#define IRQ_S5P_UART_RX0	(IRQ_S5P_UART_BASE0 + UART_IRQ_RXD)
-#define IRQ_S5P_UART_TX0	(IRQ_S5P_UART_BASE0 + UART_IRQ_TXD)
-#define IRQ_S5P_UART_ERR0	(IRQ_S5P_UART_BASE0 + UART_IRQ_ERR)
-
-#define IRQ_S5P_UART_RX1	(IRQ_S5P_UART_BASE1 + UART_IRQ_RXD)
-#define IRQ_S5P_UART_TX1	(IRQ_S5P_UART_BASE1 + UART_IRQ_TXD)
-#define IRQ_S5P_UART_ERR1	(IRQ_S5P_UART_BASE1 + UART_IRQ_ERR)
-
-#define IRQ_S5P_UART_RX2	(IRQ_S5P_UART_BASE2 + UART_IRQ_RXD)
-#define IRQ_S5P_UART_TX2	(IRQ_S5P_UART_BASE2 + UART_IRQ_TXD)
-#define IRQ_S5P_UART_ERR2	(IRQ_S5P_UART_BASE2 + UART_IRQ_ERR)
-
-#define IRQ_S5P_UART_RX3	(IRQ_S5P_UART_BASE3 + UART_IRQ_RXD)
-#define IRQ_S5P_UART_TX3	(IRQ_S5P_UART_BASE3 + UART_IRQ_TXD)
-#define IRQ_S5P_UART_ERR3	(IRQ_S5P_UART_BASE3 + UART_IRQ_ERR)
-
-/* S3C compatibilty defines */
-#define IRQ_S3CUART_RX0		IRQ_S5P_UART_RX0
-#define IRQ_S3CUART_RX1		IRQ_S5P_UART_RX1
-#define IRQ_S3CUART_RX2		IRQ_S5P_UART_RX2
-#define IRQ_S3CUART_RX3		IRQ_S5P_UART_RX3
-
 /* VIC based IRQs */
 
 #define S5P_IRQ_VIC0(x)		(S5P_VIC0_BASE + (x))

index a97c089..afdaa10 100644
@@ -17,42 +17,10 @@
 
 #include <asm/hardware/vic.h>
 
-#include <linux/serial_core.h>
 #include <mach/map.h>
 #include <plat/regs-timer.h>
-#include <plat/regs-serial.h>
 #include <plat/cpu.h>
 #include <plat/irq-vic-timer.h>
-#include <plat/irq-uart.h>
-
-/*
- * Note, we make use of the fact that the parent IRQs, IRQ_UART[0..3]
- * are consecutive when looking up the interrupt in the demux routines.
- */
-static struct s3c_uart_irq uart_irqs[] = {
-	[0] = {
-		.regs		= S5P_VA_UART0,
-		.base_irq	= IRQ_S5P_UART_BASE0,
-		.parent_irq	= IRQ_UART0,
-	},
-	[1] = {
-		.regs		= S5P_VA_UART1,
-		.base_irq	= IRQ_S5P_UART_BASE1,
-		.parent_irq	= IRQ_UART1,
-	},
-	[2] = {
-		.regs		= S5P_VA_UART2,
-		.base_irq	= IRQ_S5P_UART_BASE2,
-		.parent_irq	= IRQ_UART2,
-	},
-#if CONFIG_SERIAL_SAMSUNG_UARTS > 3
-	[3] = {
-		.regs		= S5P_VA_UART3,
-		.base_irq	= IRQ_S5P_UART_BASE3,
-		.parent_irq	= IRQ_UART3,
-	},
-#endif
-};
 
 void __init s5p_init_irq(u32 *vic, u32 num_vic)
 {

@@ -65,6 +33,4 @@ void __init s5p_init_irq(u32 *vic, u32 num_vic)
 #endif
 
 	s3c_init_vic_timer_irq(5, IRQ_TIMER0);
-
-	s3c_init_uart_irqs(uart_irqs, ARRAY_SIZE(uart_irqs));
 }

index bac36fa..7207348 100644
@@ -186,6 +186,11 @@
 #define S3C64XX_UINTSP		0x34
 #define S3C64XX_UINTM		0x38
 
+#define S3C64XX_UINTM_RXD	(0)
+#define S3C64XX_UINTM_TXD	(2)
+#define S3C64XX_UINTM_RXD_MSK	(1 << S3C64XX_UINTM_RXD)
+#define S3C64XX_UINTM_TXD_MSK	(1 << S3C64XX_UINTM_TXD)
+
 /* Following are specific to S5PV210 */
 #define S5PV210_UCON_CLKMASK	(1<<10)
 #define S5PV210_UCON_PCLK	(0<<10)

96 lines not on this page · raw message

index 76e1103..c31ae43 100644
@@ -300,6 +300,7 @@ struct uart_port {
 	void			(*set_termios)(struct uart_port *,
 				               struct ktermios *new,
 				               struct ktermios *old);
+	int			(*handle_irq)(struct uart_port *);
 	void			(*pm)(struct uart_port *, unsigned int state,
 				      unsigned int old);
 	unsigned int		irq;			/* irq number */

index f2dfec8..833e011 100644
@@ -509,6 +509,8 @@ static void io_serial_out(struct uart_port *p, int offset, int value)
 	outb(value, p->iobase + offset);
 }
 
+static int serial8250_default_handle_irq(struct uart_port *port);
+
 static void set_io_from_upio(struct uart_port *p)
 {
 	struct uart_8250_port *up =

@@ -557,6 +559,7 @@ static void set_io_from_upio(struct uart_port *p)
 	}
 	/* Remember loaded iotype */
 	up->cur_iotype = p->iotype;
+	p->handle_irq = serial8250_default_handle_irq;
 }
 
 static void

@@ -1621,6 +1624,28 @@ static void serial8250_handle_port(struct uart_8250_port *up)
 	spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
+int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+
+	if (!(iir & UART_IIR_NO_INT)) {
+		serial8250_handle_port(up);
+		return 1;
+	}
+
+	return 0;
+}
+
+static int serial8250_default_handle_irq(struct uart_port *port)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+	unsigned int iir = serial_in(up, UART_IIR);
+
+	return serial8250_handle_irq(port, iir);
+}
+
 /*
  * This is the serial driver's interrupt routine.
  *

@@ -1648,13 +1673,12 @@ static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
 	l = i->head;
 	do {
 		struct uart_8250_port *up;
-		unsigned int iir;
+		struct uart_port *port;
 
 		up = list_entry(l, struct uart_8250_port, list);
+		port = &up->port;
 
-		iir = serial_in(up, UART_IIR);
-		if (!(iir & UART_IIR_NO_INT)) {
-			serial8250_handle_port(up);
+		if (port->handle_irq(port)) {
 
 			handled = 1;
 

@@ -3048,6 +3072,10 @@ int __init early_serial_setup(struct uart_port *port)
 		p->serial_in = port->serial_in;
 	if (port->serial_out)
 		p->serial_out = port->serial_out;
+	if (port->handle_irq)
+		p->handle_irq = port->handle_irq;
+	else
+		p->handle_irq = serial8250_default_handle_irq;
 
 	return 0;
 }

@@ -3116,6 +3144,7 @@ static int __devinit serial8250_probe(struct platform_device *dev)
 		port.type		= p->type;
 		port.serial_in		= p->serial_in;
 		port.serial_out		= p->serial_out;
+		port.handle_irq		= p->handle_irq;
 		port.set_termios	= p->set_termios;
 		port.pm			= p->pm;
 		port.dev		= &dev->dev;

@@ -3281,6 +3310,8 @@ int serial8250_register_port(struct uart_port *port)
 			uart->port.serial_in = port->serial_in;
 		if (port->serial_out)
 			uart->port.serial_out = port->serial_out;
+		if (port->handle_irq)
+			uart->port.handle_irq = port->handle_irq;
 		/*  Possibly override set_termios call */
 		if (port->set_termios)
 			uart->port.set_termios = port->set_termios;

index 97f5b45..1f05bbe 100644
@@ -35,6 +35,7 @@ struct plat_serial8250_port {
 	void		(*set_termios)(struct uart_port *,
 			               struct ktermios *new,
 			               struct ktermios *old);
+	int		(*handle_irq)(struct uart_port *);
 	void		(*pm)(struct uart_port *, unsigned int state,
 			      unsigned old);
 };

@@ -80,6 +81,7 @@ extern void serial8250_do_set_termios(struct uart_port *port,
 		struct ktermios *termios, struct ktermios *old);
 extern void serial8250_do_pm(struct uart_port *port, unsigned int state,
 			     unsigned int oldstate);
+int serial8250_handle_irq(struct uart_port *port, unsigned int iir);
 
 extern void serial8250_set_isa_configurator(void (*v)
 					(int port, struct uart_port *up,

index f726162..c3247b5 100644
@@ -65,7 +65,7 @@ void __init msp_serial_setup(void)
 	up.line         = 0;
 	up.private_data		= (void*)UART0_STATUS_REG;
 	if (early_serial_setup(&up))
-		printk(KERN_ERR "Early serial init of port 0 failed\n");
+		pr_err("Early serial init of port 0 failed\n");
 
 	/* Initialize the second serial port, if one exists */
 	switch (mips_machtype) {

@@ -89,5 +89,5 @@ void __init msp_serial_setup(void)
 	up.line         = 1;
 	up.private_data		= (void*)UART1_STATUS_REG;
 	if (early_serial_setup(&up))
-		printk(KERN_ERR "Early serial init of port 1 failed\n");
+		pr_err("Early serial init of port 1 failed\n");
 }

index c3247b5..a1c7c7d 100644
@@ -27,6 +27,7 @@
 #include <linux/serial.h>
 #include <linux/serial_core.h>
 #include <linux/serial_reg.h>
+#include <linux/slab.h>
 
 #include <asm/bootinfo.h>
 #include <asm/io.h>

@@ -38,6 +39,55 @@
 #include <msp_int.h>
 #include <msp_regs.h>
 
+struct msp_uart_data {
+	int	last_lcr;
+};
+
+static void msp_serial_out(struct uart_port *p, int offset, int value)
+{
+	struct msp_uart_data *d = p->private_data;
+
+	if (offset == UART_LCR)
+		d->last_lcr = value;
+
+	offset <<= p->regshift;
+	writeb(value, p->membase + offset);
+}
+
+static unsigned int msp_serial_in(struct uart_port *p, int offset)
+{
+	offset <<= p->regshift;
+
+	return readb(p->membase + offset);
+}
+
+static int msp_serial_handle_irq(struct uart_port *p)
+{
+	struct msp_uart_data *d = p->private_data;
+	unsigned int iir = readb(p->membase + (UART_IIR << p->regshift));
+
+	if (serial8250_handle_irq(p, iir)) {
+		return 1;
+	} else if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
+		/*
+		 * The DesignWare APB UART has an Busy Detect (0x07) interrupt
+		 * meaning an LCR write attempt occurred while the UART was
+		 * busy. The interrupt must be cleared by reading the UART
+		 * status register (USR) and the LCR re-written.
+		 *
+		 * Note: MSP reserves 0x20 bytes of address space for the UART
+		 * and the USR is mapped in a separate block at an offset of
+		 * 0xc0 from the start of the UART.
+		 */
+		(void)readb(p->membase + 0xc0);
+		writeb(d->last_lcr, p->membase + (UART_LCR << p->regshift));
+
+		return 1;
+	}
+
+	return 0;
+}
+
 void __init msp_serial_setup(void)
 {
 	char    *s;

@@ -59,13 +109,22 @@ void __init msp_serial_setup(void)
 	up.irq          = MSP_INT_UART0;
 	up.uartclk      = uartclk;
 	up.regshift     = 2;
-	up.iotype       = UPIO_DWAPB; /* UPIO_MEM like */
+	up.iotype       = UPIO_MEM;
 	up.flags        = ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST;
 	up.type         = PORT_16550A;
 	up.line         = 0;
-	up.private_data		= (void*)UART0_STATUS_REG;
-	if (early_serial_setup(&up))
+	up.serial_out	= msp_serial_out;
+	up.serial_in	= msp_serial_in;
+	up.handle_irq	= msp_serial_handle_irq;
+	up.private_data	= kzalloc(sizeof(struct msp_uart_data), GFP_KERNEL);
+	if (!up.private_data) {
+		pr_err("failed to allocate uart private data\n");
+		return;
+	}
+	if (early_serial_setup(&up)) {
+		kfree(up.private_data);
 		pr_err("Early serial init of port 0 failed\n");
+	}
 
 	/* Initialize the second serial port, if one exists */
 	switch (mips_machtype) {

@@ -88,6 +147,8 @@ void __init msp_serial_setup(void)
 	up.irq          = MSP_INT_UART1;
 	up.line         = 1;
 	up.private_data		= (void*)UART1_STATUS_REG;
-	if (early_serial_setup(&up))
+	if (early_serial_setup(&up)) {
+		kfree(up.private_data);
 		pr_err("Early serial init of port 1 failed\n");
+	}
 }

index 833e011..6f594d2 100644
@@ -461,42 +461,6 @@ static void tsi_serial_out(struct uart_port *p, int offset, int value)
 		writeb(value, p->membase + offset);
 }
 
-/* Save the LCR value so it can be re-written when a Busy Detect IRQ occurs. */
-static inline void dwapb_save_out_value(struct uart_port *p, int offset,
-					int value)
-{
-	struct uart_8250_port *up =
-		container_of(p, struct uart_8250_port, port);
-
-	if (offset == UART_LCR)
-		up->lcr = value;
-}
-
-/* Read the IER to ensure any interrupt is cleared before returning from ISR. */
-static inline void dwapb_check_clear_ier(struct uart_port *p, int offset)
-{
-	if (offset == UART_TX || offset == UART_IER)
-		p->serial_in(p, UART_IER);
-}
-
-static void dwapb_serial_out(struct uart_port *p, int offset, int value)
-{
-	int save_offset = offset;
-	offset = map_8250_out_reg(p, offset) << p->regshift;
-	dwapb_save_out_value(p, save_offset, value);
-	writeb(value, p->membase + offset);
-	dwapb_check_clear_ier(p, save_offset);
-}
-
-static void dwapb32_serial_out(struct uart_port *p, int offset, int value)
-{
-	int save_offset = offset;
-	offset = map_8250_out_reg(p, offset) << p->regshift;
-	dwapb_save_out_value(p, save_offset, value);
-	writel(value, p->membase + offset);
-	dwapb_check_clear_ier(p, save_offset);
-}
-
 static unsigned int io_serial_in(struct uart_port *p, int offset)
 {
 	offset = map_8250_in_reg(p, offset) << p->regshift;

@@ -542,16 +506,6 @@ static void set_io_from_upio(struct uart_port *p)
 		p->serial_out = tsi_serial_out;
 		break;
 
-	case UPIO_DWAPB:
-		p->serial_in = mem_serial_in;
-		p->serial_out = dwapb_serial_out;
-		break;
-
-	case UPIO_DWAPB32:
-		p->serial_in = mem32_serial_in;
-		p->serial_out = dwapb32_serial_out;
-		break;
-
 	default:
 		p->serial_in = io_serial_in;
 		p->serial_out = io_serial_out;

@@ -570,8 +524,6 @@ serial_out_sync(struct uart_8250_port *up, int offset, int value)
 	case UPIO_MEM:
 	case UPIO_MEM32:
 	case UPIO_AU:
-	case UPIO_DWAPB:
-	case UPIO_DWAPB32:
 		p->serial_out(p, offset, value);
 		p->serial_in(p, UART_LCR);	/* safe, no side-effects */
 		break;

@@ -1679,23 +1631,7 @@ static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
 		port = &up->port;
 
 		if (port->handle_irq(port)) {
-
 			handled = 1;
-
-			end = NULL;
-		} else if ((up->port.iotype == UPIO_DWAPB ||
-			    up->port.iotype == UPIO_DWAPB32) &&
-			  (iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
-			/* The DesignWare APB UART has an Busy Detect (0x07)
-			 * interrupt meaning an LCR write attempt occurred while the
-			 * UART was busy. The interrupt must be cleared by reading
-			 * the UART status register (USR) and the LCR re-written. */
-			unsigned int status;
-			status = *(volatile u32 *)up->port.private_data;
-			serial_out(up, UART_LCR, up->lcr);
-
-			handled = 1;
-
 			end = NULL;
 		} else if (end == NULL)
 			end = l;

@@ -2592,8 +2528,6 @@ static int serial8250_request_std_resource(struct uart_8250_port *up)
 	case UPIO_TSI:
 	case UPIO_MEM32:
 	case UPIO_MEM:
-	case UPIO_DWAPB:
-	case UPIO_DWAPB32:
 		if (!up->port.mapbase)
 			break;
 

@@ -2630,8 +2564,6 @@ static void serial8250_release_std_resource(struct uart_8250_port *up)
 	case UPIO_TSI:
 	case UPIO_MEM32:
 	case UPIO_MEM:
-	case UPIO_DWAPB:
-	case UPIO_DWAPB32:
 		if (!up->port.mapbase)
 			break;
 

index 44c2963..3844980 100644
@@ -2032,8 +2032,6 @@ uart_report_port(struct uart_driver *drv, struct uart_port *port)
 	case UPIO_MEM32:
 	case UPIO_AU:
 	case UPIO_TSI:
-	case UPIO_DWAPB:
-	case UPIO_DWAPB32:
 		snprintf(address, sizeof(address),
 			 "MMIO 0x%llx", (unsigned long long)port->mapbase);
 		break;

@@ -2446,8 +2444,6 @@ int uart_match_port(struct uart_port *port1, struct uart_port *port2)
 	case UPIO_MEM32:
 	case UPIO_AU:
 	case UPIO_TSI:
-	case UPIO_DWAPB:
-	case UPIO_DWAPB32:
 		return (port1->mapbase == port2->mapbase);
 	}
 	return 0;

index c31ae43..493773e 100644
@@ -318,9 +318,7 @@ struct uart_port {
 #define UPIO_MEM32		(3)
 #define UPIO_AU			(4)			/* Au1x00 type IO */
 #define UPIO_TSI		(5)			/* Tsi108/109 type IO */
-#define UPIO_DWAPB		(6)			/* DesignWare APB UART */
-#define UPIO_RM9000		(7)			/* RM9000 type IO */
-#define UPIO_DWAPB32		(8)			/* DesignWare APB UART (32 bit accesses) */
+#define UPIO_RM9000		(6)			/* RM9000 type IO */
 
 	unsigned int		read_status_mask;	/* driver specific */
 	unsigned int		ignore_status_mask;	/* driver specific */

new file mode 100644
index 0000000..e25782a
@@ -0,0 +1,99 @@
+/*
+ * Synopsys DesignWare specific 8250 operations.
+ *
+ * Copyright 2011 Picochip, Jamie Iles.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * The Synopsys DesignWare 8250 has an extra feature whereby it detects if the
+ * LCR is written whilst busy.  If it is, then a busy detect interrupt is
+ * raised, the LCR needs to be rewritten and the uart status register read.
+ */
+#include <linux/io.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+#include <linux/slab.h>
+
+struct dw8250_data {
+	int	last_lcr;
+};
+
+static void dw8250_serial_out(struct uart_port *p, int offset, int value)
+{
+	struct dw8250_data *d = p->private_data;
+
+	if (offset == UART_LCR)
+		d->last_lcr = value;
+
+	offset <<= p->regshift;
+	writeb(value, p->membase + offset);
+}
+
+static unsigned int dw8250_serial_in(struct uart_port *p, int offset)
+{
+	offset <<= p->regshift;
+
+	return readb(p->membase + offset);
+}
+
+static void dw8250_serial_out32(struct uart_port *p, int offset,
+				int value)
+{
+	struct dw8250_data *d = p->private_data;
+
+	if (offset == UART_LCR)
+		d->last_lcr = value;
+
+	offset <<= p->regshift;
+	writel(value, p->membase + offset);
+}
+
+static unsigned int dw8250_serial_in32(struct uart_port *p, int offset)
+{
+	offset <<= p->regshift;
+
+	return readl(p->membase + offset);
+}
+
+/* Offset for the DesignWare's UART Status Register. */
+#define UART_USR	0x1f
+
+static int dw8250_handle_irq(struct uart_port *p)
+{
+	struct dw8250_data *d = p->private_data;
+	unsigned int iir = p->serial_in(p, UART_IIR);
+
+	if (serial8250_handle_irq(p, iir)) {
+		return 1;
+	} else if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
+		/* Clear the USR and write the LCR again. */
+		(void)p->serial_in(p, UART_USR);
+		p->serial_out(p, d->last_lcr, UART_LCR);
+
+		return 1;
+	}
+
+	return 0;
+}
+
+int serial8250_use_designware_io(struct uart_port *up)
+{
+	up->private_data = kzalloc(sizeof(struct dw8250_data), GFP_KERNEL);
+	if (!up->private_data)
+		return -ENOMEM;
+
+	if (up->iotype == UPIO_MEM32) {
+		up->serial_out = dw8250_serial_out32;
+		up->serial_in = dw8250_serial_in32;
+	} else {
+		up->serial_out = dw8250_serial_out;
+		up->serial_in = dw8250_serial_in;
+	}
+	up->handle_irq = dw8250_handle_irq;
+
+	return 0;
+}

index 1f05bbe..09e2dbc 100644
@@ -86,5 +86,13 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir);
 extern void serial8250_set_isa_configurator(void (*v)
 					(int port, struct uart_port *up,
 						unsigned short *capabilities));
+#ifndef SERIAL_8250_DW
+extern int serial8250_use_designware_io(struct uart_port *up);
+#else
+static inline int serial8250_use_designware_io(struct uart_port *up)
+{
+	return -EIO;
+}
+#endif
 
 #endif

index e58cece..024926c 100644
@@ -78,6 +78,12 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
 		}
 	}
 
+	if (of_device_is_compatible(np, "ns8250dw")) {
+		ret = serial8250_use_designware_io(port);
+		if (ret)
+			dev_warn(&ofdev->dev, "unable to register DesignWare 8250 helpers, continuing as a normal 8250\n");
+	}
+
 	port->type = type;
 	port->uartclk = clk;
 	port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP

@@ -176,6 +182,7 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
  */
 static struct of_device_id __devinitdata of_platform_serial_table[] = {
 	{ .compatible = "ns8250",   .data = (void *)PORT_8250, },
+	{ .compatible = "ns8250dw", .data = (void *)PORT_8250, },
 	{ .compatible = "ns16450",  .data = (void *)PORT_16450, },
 	{ .compatible = "ns16550a", .data = (void *)PORT_16550A, },
 	{ .compatible = "ns16550",  .data = (void *)PORT_16550, },

index 024926c..e58cece 100644
@@ -78,12 +78,6 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
 		}
 	}
 
-	if (of_device_is_compatible(np, "ns8250dw")) {
-		ret = serial8250_use_designware_io(port);
-		if (ret)
-			dev_warn(&ofdev->dev, "unable to register DesignWare 8250 helpers, continuing as a normal 8250\n");
-	}
-
 	port->type = type;
 	port->uartclk = clk;
 	port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP

@@ -182,7 +176,6 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
  */
 static struct of_device_id __devinitdata of_platform_serial_table[] = {
 	{ .compatible = "ns8250",   .data = (void *)PORT_8250, },
-	{ .compatible = "ns8250dw", .data = (void *)PORT_8250, },
 	{ .compatible = "ns16450",  .data = (void *)PORT_16450, },
 	{ .compatible = "ns16550a", .data = (void *)PORT_16550A, },
 	{ .compatible = "ns16550",  .data = (void *)PORT_16550, },

deleted file mode 100644
index e25782a..0000000
@@ -1,99 +0,0 @@
-/*
- * Synopsys DesignWare specific 8250 operations.
- *
- * Copyright 2011 Picochip, Jamie Iles.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * The Synopsys DesignWare 8250 has an extra feature whereby it detects if the
- * LCR is written whilst busy.  If it is, then a busy detect interrupt is
- * raised, the LCR needs to be rewritten and the uart status register read.
- */
-#include <linux/io.h>
-#include <linux/serial_8250.h>
-#include <linux/serial_core.h>
-#include <linux/serial_reg.h>
-#include <linux/slab.h>
-
-struct dw8250_data {
-	int	last_lcr;
-};
-
-static void dw8250_serial_out(struct uart_port *p, int offset, int value)
-{
-	struct dw8250_data *d = p->private_data;
-
-	if (offset == UART_LCR)
-		d->last_lcr = value;
-
-	offset <<= p->regshift;
-	writeb(value, p->membase + offset);
-}
-
-static unsigned int dw8250_serial_in(struct uart_port *p, int offset)
-{
-	offset <<= p->regshift;
-
-	return readb(p->membase + offset);
-}
-
-static void dw8250_serial_out32(struct uart_port *p, int offset,
-				int value)
-{
-	struct dw8250_data *d = p->private_data;
-
-	if (offset == UART_LCR)
-		d->last_lcr = value;
-
-	offset <<= p->regshift;
-	writel(value, p->membase + offset);
-}
-
-static unsigned int dw8250_serial_in32(struct uart_port *p, int offset)
-{
-	offset <<= p->regshift;
-
-	return readl(p->membase + offset);
-}
-
-/* Offset for the DesignWare's UART Status Register. */
-#define UART_USR	0x1f
-
-static int dw8250_handle_irq(struct uart_port *p)
-{
-	struct dw8250_data *d = p->private_data;
-	unsigned int iir = p->serial_in(p, UART_IIR);
-
-	if (serial8250_handle_irq(p, iir)) {
-		return 1;
-	} else if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
-		/* Clear the USR and write the LCR again. */
-		(void)p->serial_in(p, UART_USR);
-		p->serial_out(p, d->last_lcr, UART_LCR);
-
-		return 1;
-	}
-
-	return 0;
-}
-
-int serial8250_use_designware_io(struct uart_port *up)
-{
-	up->private_data = kzalloc(sizeof(struct dw8250_data), GFP_KERNEL);
-	if (!up->private_data)
-		return -ENOMEM;
-
-	if (up->iotype == UPIO_MEM32) {
-		up->serial_out = dw8250_serial_out32;
-		up->serial_in = dw8250_serial_in32;
-	} else {
-		up->serial_out = dw8250_serial_out;
-		up->serial_in = dw8250_serial_in;
-	}
-	up->handle_irq = dw8250_handle_irq;
-
-	return 0;
-}

index 09e2dbc..1f05bbe 100644
@@ -86,13 +86,5 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir);
 extern void serial8250_set_isa_configurator(void (*v)
 					(int port, struct uart_port *up,
 						unsigned short *capabilities));
-#ifndef SERIAL_8250_DW
-extern int serial8250_use_designware_io(struct uart_port *up);
-#else
-static inline int serial8250_use_designware_io(struct uart_port *up)
-{
-	return -EIO;
-}
-#endif
 
 #endif

index 7e91b3d..54ffdc6 100644
@@ -508,8 +508,10 @@ static irqreturn_t imx_rxint(int irq, void *dev_id)
 		if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
 			continue;
 
-		if (rx & (URXD_PRERR | URXD_OVRRUN | URXD_FRMERR) ) {
-			if (rx & URXD_PRERR)
+		if (unlikely(rx & URXD_ERR)) {
+			if (rx & URXD_BRK)
+				sport->port.icount.brk++;
+			else if (rx & URXD_PRERR)
 				sport->port.icount.parity++;
 			else if (rx & URXD_FRMERR)
 				sport->port.icount.frame++;

@@ -524,7 +526,9 @@ static irqreturn_t imx_rxint(int irq, void *dev_id)
 
 			rx &= sport->port.read_status_mask;
 
-			if (rx & URXD_PRERR)
+			if (rx & URXD_BRK)
+				flg = TTY_BREAK;
+			else if (rx & URXD_PRERR)
 				flg = TTY_PARITY;
 			else if (rx & URXD_FRMERR)
 				flg = TTY_FRAME;

index af9b781..c7232a9 100644
@@ -339,7 +339,8 @@ static void atmel_stop_tx(struct uart_port *port)
 	/* Disable interrupts */
 	UART_PUT_IDR(port, atmel_port->tx_done_mask);
 
-	if (atmel_port->rs485.flags & SER_RS485_ENABLED)
+	if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
+	    !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX))
 		atmel_start_rx(port);
 }
 

@@ -356,7 +357,8 @@ static void atmel_start_tx(struct uart_port *port)
 			   really need this.*/
 			return;
 
-		if (atmel_port->rs485.flags & SER_RS485_ENABLED)
+		if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
+		    !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX))
 			atmel_stop_rx(port);
 
 		/* re-enable PDC transmit */

@@ -680,7 +682,8 @@ static void atmel_tx_dma(struct uart_port *port)
 		/* Enable interrupts */
 		UART_PUT_IER(port, atmel_port->tx_done_mask);
 	} else {
-		if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
+		if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
+		    !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX)) {
 			/* DMA done, stop TX, start RX for RS485 */
 			atmel_start_rx(port);
 		}

index ef91406..97ff8e2 100644
@@ -211,6 +211,7 @@ struct serial_rs485 {
 #define SER_RS485_RTS_ON_SEND		(1 << 1)
 #define SER_RS485_RTS_AFTER_SEND	(1 << 2)
 #define SER_RS485_RTS_BEFORE_SEND	(1 << 3)
+#define SER_RS485_RX_DURING_TX		(1 << 4)
 	__u32	delay_rts_before_send;	/* Milliseconds */
 	__u32	delay_rts_after_send;	/* Milliseconds */
 	__u32	padding[5];		/* Memory is cheap, new structs

index b704c8c..cd53bdd 100644
@@ -88,7 +88,6 @@ enum {
 
 /* 4 extra for alignment play space */
 #define WRITEBUFLEN	((4096) + 4)
-#define MYFLIPLEN	N_TTY_BUF_SIZE
 
 #define JSM_VERSION	"jsm: 1.2-1-INKERNEL"
 #define JSM_PARTNUM	"40002438_A-INKERNEL"

@@ -150,7 +149,6 @@ struct jsm_board
 	u32		bd_uart_offset;	/* Space between each UART */
 
 	struct jsm_channel *channels[MAXPORTS]; /* array of pointers to our channels. */
-	char		*flipbuf;	/* Our flip buffer, alloced if board is found */
 
 	u32		bd_dividend;	/* Board/UARTs specific dividend */
 

@@ -177,7 +175,6 @@ struct jsm_board
 #define CH_TX_FIFO_LWM	0x0800		/* TX Fifo is below Low Water	*/
 #define CH_BREAK_SENDING 0x1000		/* Break is being sent		*/
 #define CH_LOOPBACK 0x2000		/* Channel is in lookback mode	*/
-#define CH_FLIPBUF_IN_USE 0x4000	/* Channel's flipbuf is in use	*/
 #define CH_BAUD0	0x08000		/* Used for checking B0 transitions */
 
 /* Our Read/Error/Write queue sizes */

index 96da178..1cc8cf6 100644
@@ -160,27 +160,10 @@ static int __devinit jsm_probe_one(struct pci_dev *pdev, const struct pci_device
 	dev_info(&pdev->dev, "board %d: Digi Neo (rev %d), irq %d\n",
 			adapter_count, brd->rev, brd->irq);
 
-	/*
-	 * allocate flip buffer for board.
-	 *
-	 * Okay to malloc with GFP_KERNEL, we are not at interrupt
-	 * context, and there are no locks held.
-	 */
-	brd->flipbuf = kzalloc(MYFLIPLEN, GFP_KERNEL);
-	if (!brd->flipbuf) {
-		/* XXX: leaking all resources from jsm_tty_init and
-		 	jsm_uart_port_init here! */
-		dev_err(&pdev->dev, "memory allocation for flipbuf failed\n");
-		rc = -ENOMEM;
-		goto out_free_uart;
-	}
-
 	pci_set_drvdata(pdev, brd);
 	pci_save_state(pdev);
 
 	return 0;
- out_free_uart:
-	jsm_remove_uart_port(brd);
  out_free_irq:
 	jsm_remove_uart_port(brd);
 	free_irq(brd->irq, brd);

@@ -218,7 +201,6 @@ static void __devexit jsm_remove_one(struct pci_dev *pdev)
 
 	pci_release_regions(pdev);
 	pci_disable_device(pdev);
-	kfree(brd->flipbuf);
 	kfree(brd);
 }
 

index cd53bdd..529bec6 100644
@@ -180,10 +180,8 @@ struct jsm_board
 /* Our Read/Error/Write queue sizes */
 #define RQUEUEMASK	0x1FFF		/* 8 K - 1 */
 #define EQUEUEMASK	0x1FFF		/* 8 K - 1 */
-#define WQUEUEMASK	0x0FFF		/* 4 K - 1 */
 #define RQUEUESIZE	(RQUEUEMASK + 1)
 #define EQUEUESIZE	RQUEUESIZE
-#define WQUEUESIZE	(WQUEUEMASK + 1)
 
 
 /************************************************************************

@@ -223,10 +221,6 @@ struct jsm_channel {
 	u16		ch_e_head;	/* Head location of the error queue */
 	u16		ch_e_tail;	/* Tail location of the error queue */
 
-	u8		*ch_wqueue;	/* Our write queue buffer - malloc'ed */
-	u16		ch_w_head;	/* Head location of the write queue */
-	u16		ch_w_tail;	/* Tail location of the write queue */
-
 	u64		ch_rxcount;	/* total of data received so far */
 	u64		ch_txcount;	/* total of data transmitted so far */
 

@@ -375,7 +369,6 @@ extern int	jsm_debug;
  * Prototypes for non-static functions used in more than one module
  *
  *************************************************************************/
-int jsm_tty_write(struct uart_port *port);
 int jsm_tty_init(struct jsm_board *);
 int jsm_uart_port_init(struct jsm_board *);
 int jsm_remove_uart_port(struct jsm_board *);

index 1cc8cf6..648b6a3 100644
@@ -194,7 +194,6 @@ static void __devexit jsm_remove_one(struct pci_dev *pdev)
 		if (brd->channels[i]) {
 			kfree(brd->channels[i]->ch_rqueue);
 			kfree(brd->channels[i]->ch_equeue);
-			kfree(brd->channels[i]->ch_wqueue);
 			kfree(brd->channels[i]);
 		}
 	}

index 4538c3e..bd6e846 100644
@@ -496,12 +496,15 @@ static void neo_copy_data_from_queue_to_uart(struct jsm_channel *ch)
 	int s;
 	int qlen;
 	u32 len_written = 0;
+	struct circ_buf *circ;
 
 	if (!ch)
 		return;
 
+	circ = &ch->uart_port.state->xmit;
+
 	/* No data to write to the UART */
-	if (ch->ch_w_tail == ch->ch_w_head)
+	if (uart_circ_empty(circ))
 		return;
 
 	/* If port is "stopped", don't send any data to the UART */

@@ -517,11 +520,10 @@ static void neo_copy_data_from_queue_to_uart(struct jsm_channel *ch)
 		if (ch->ch_cached_lsr & UART_LSR_THRE) {
 			ch->ch_cached_lsr &= ~(UART_LSR_THRE);
 
-			writeb(ch->ch_wqueue[ch->ch_w_tail], &ch->ch_neo_uart->txrx);
+			writeb(circ->buf[circ->tail], &ch->ch_neo_uart->txrx);
 			jsm_printk(WRITE, INFO, &ch->ch_bd->pci_dev,
-					"Tx data: %x\n", ch->ch_wqueue[ch->ch_w_head]);
-			ch->ch_w_tail++;
-			ch->ch_w_tail &= WQUEUEMASK;
+					"Tx data: %x\n", circ->buf[circ->head]);
+			circ->tail = (circ->tail + 1) & (UART_XMIT_SIZE - 1);
 			ch->ch_txcount++;
 		}
 		return;

@@ -536,36 +538,36 @@ static void neo_copy_data_from_queue_to_uart(struct jsm_channel *ch)
 	n = UART_17158_TX_FIFOSIZE - ch->ch_t_tlevel;
 
 	/* cache head and tail of queue */
-	head = ch->ch_w_head & WQUEUEMASK;
-	tail = ch->ch_w_tail & WQUEUEMASK;
-	qlen = (head - tail) & WQUEUEMASK;
+	head = circ->head & (UART_XMIT_SIZE - 1);
+	tail = circ->tail & (UART_XMIT_SIZE - 1);
+	qlen = uart_circ_chars_pending(circ);
 
 	/* Find minimum of the FIFO space, versus queue length */
 	n = min(n, qlen);
 
 	while (n > 0) {
 
-		s = ((head >= tail) ? head : WQUEUESIZE) - tail;
+		s = ((head >= tail) ? head : UART_XMIT_SIZE) - tail;
 		s = min(s, n);
 
 		if (s <= 0)
 			break;
 
-		memcpy_toio(&ch->ch_neo_uart->txrxburst, ch->ch_wqueue + tail, s);
+		memcpy_toio(&ch->ch_neo_uart->txrxburst, circ->buf + tail, s);
 		/* Add and flip queue if needed */
-		tail = (tail + s) & WQUEUEMASK;
+		tail = (tail + s) & (UART_XMIT_SIZE - 1);
 		n -= s;
 		ch->ch_txcount += s;
 		len_written += s;
 	}
 
 	/* Update the final tail */
-	ch->ch_w_tail = tail & WQUEUEMASK;
+	circ->tail = tail & (UART_XMIT_SIZE - 1);
 
 	if (len_written >= ch->ch_t_tlevel)
 		ch->ch_flags &= ~(CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 
-	if (!jsm_tty_write(&ch->uart_port))
+	if (uart_circ_empty(circ))
 		uart_write_wakeup(&ch->uart_port);
 }
 

@@ -946,7 +948,6 @@ static void neo_param(struct jsm_channel *ch)
 	if ((ch->ch_c_cflag & (CBAUD)) == 0) {
 		ch->ch_r_head = ch->ch_r_tail = 0;
 		ch->ch_e_head = ch->ch_e_tail = 0;
-		ch->ch_w_head = ch->ch_w_tail = 0;
 
 		neo_flush_uart_write(ch);
 		neo_flush_uart_read(ch);

115 lines not on this page · raw message

index bd6e846..81dfafa 100644
@@ -522,7 +522,7 @@ static void neo_copy_data_from_queue_to_uart(struct jsm_channel *ch)
 
 			writeb(circ->buf[circ->tail], &ch->ch_neo_uart->txrx);
 			jsm_printk(WRITE, INFO, &ch->ch_bd->pci_dev,
-					"Tx data: %x\n", circ->buf[circ->head]);
+					"Tx data: %x\n", circ->buf[circ->tail]);
 			circ->tail = (circ->tail + 1) & (UART_XMIT_SIZE - 1);
 			ch->ch_txcount++;
 		}

index 3844980..849bd0d 100644
@@ -1288,6 +1288,7 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 	 * the line discipline to only process XON/XOFF characters by
 	 * setting tty->closing.
 	 */
+	set_bit(ASYNCB_CLOSING, &port->flags);
 	tty->closing = 1;
 	spin_unlock_irqrestore(&port->lock, flags);
 

@@ -1335,8 +1336,10 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 	 * Wake up anyone trying to open this port.
 	 */
 	clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
+	clear_bit(ASYNCB_CLOSING, &port->flags);
 	spin_unlock_irqrestore(&port->lock, flags);
 	wake_up_interruptible(&port->open_wait);
+	wake_up_interruptible(&port->close_wait);
 
 done:
 	mutex_unlock(&port->mutex);

index 849bd0d..0464360 100644
@@ -1253,7 +1253,6 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 
 	pr_debug("uart_close(%d) called\n", uport->line);
 
-	mutex_lock(&port->mutex);
 	spin_lock_irqsave(&port->lock, flags);
 
 	if (tty_hung_up_p(filp)) {

@@ -1312,6 +1311,7 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 		uart_wait_until_sent(tty, uport->timeout);
 	}
 
+	mutex_lock(&port->mutex);
 	uart_shutdown(tty, state);
 	uart_flush_buffer(tty);
 

index 6d5eceb..0ad6888 100644
@@ -602,6 +602,24 @@ extern void __lockfunc tty_lock(void) __acquires(tty_lock);
 extern void __lockfunc tty_unlock(void) __releases(tty_lock);
 
 /*
+ * this shall be called only from where BTM is held (like close)
+ *
+ * We need this to ensure nobody waits for us to finish while we are waiting.
+ * Without this we were encountering system stalls.
+ *
+ * This should be indeed removed with BTM removal later.
+ *
+ * Locking: BTM required. Nobody is allowed to hold port->mutex.
+ */
+static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
+		long timeout)
+{
+	tty_unlock(); /* tty->ops->close holds the BTM, drop it while waiting */
+	tty_wait_until_sent(tty, timeout);
+	tty_lock();
+}
+
+/*
  * wait_event_interruptible_tty -- wait for a condition with the tty lock held
  *
  * The condition we are waiting for might take a long time to

index 33d37d2..ef9dd62 100644
@@ -350,7 +350,7 @@ int tty_port_close_start(struct tty_port *port,
 		tty_driver_flush_buffer(tty);
 	if (test_bit(ASYNCB_INITIALIZED, &port->flags) &&
 			port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
-		tty_wait_until_sent(tty, port->closing_wait);
+		tty_wait_until_sent_from_close(tty, port->closing_wait);
 	if (port->drain_delay) {
 		unsigned int bps = tty_get_baud_rate(tty);
 		long timeout;

index d850427..e5546cb 100644
@@ -1693,7 +1693,7 @@ isdn_tty_close(struct tty_struct *tty, struct file *filp)
 	 * line status register.
 	 */
 	if (info->flags & ISDN_ASYNC_INITIALIZED) {
-		tty_wait_until_sent(tty, 3000);	/* 30 seconds timeout */
+		tty_wait_until_sent_from_close(tty, 3000);	/* 30 seconds timeout */
 		/*
 		 * Before we drop DTR, make sure the UART transmitter
 		 * has completely drained; this is especially

index e1aaf4f..b6b2d18 100644
@@ -388,7 +388,7 @@ static void hvc_close(struct tty_struct *tty, struct file * filp)
 		 * there is no buffered data otherwise sleeps on a wait queue
 		 * waking periodically to check chars_in_buffer().
 		 */
-		tty_wait_until_sent(tty, HVC_CLOSE_WAIT);
+		tty_wait_until_sent_from_close(tty, HVC_CLOSE_WAIT);
 	} else {
 		if (hp->count < 0)
 			printk(KERN_ERR "hvc_close %X: oops, count is %d\n",

index 4c8b665..e523773 100644
@@ -1237,7 +1237,7 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp)
 		irq = hvcsd->vdev->irq;
 		spin_unlock_irqrestore(&hvcsd->lock, flags);
 
-		tty_wait_until_sent(tty, HVCS_CLOSE_WAIT);
+		tty_wait_until_sent_from_close(tty, HVCS_CLOSE_WAIT);
 
 		/*
 		 * This line is important because it tells hvcs_open that this

index 0464360..1d3780c 100644
@@ -1292,7 +1292,8 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 	spin_unlock_irqrestore(&port->lock, flags);
 
 	if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
-		tty_wait_until_sent(tty, msecs_to_jiffies(port->closing_wait));
+		tty_wait_until_sent_from_close(tty,
+				msecs_to_jiffies(port->closing_wait));
 
 	/*
 	 * At this point, we stop accepting input.  To do this, we

index b3cc8b3..253695d 100644
@@ -551,7 +551,7 @@ static void ircomm_tty_close(struct tty_struct *tty, struct file *filp)
 	 */
 	tty->closing = 1;
 	if (self->closing_wait != ASYNC_CLOSING_WAIT_NONE)
-		tty_wait_until_sent(tty, self->closing_wait);
+		tty_wait_until_sent_from_close(tty, self->closing_wait);
 
 	ircomm_tty_shutdown(self);
 

index cab52f4..cfa7501 100644
@@ -38,6 +38,7 @@
 #include <linux/pci.h>
 #include <linux/io.h>
 #include <linux/debugfs.h>
+#include <linux/pm_runtime.h>
 
 #define HSU_DMA_BUF_SIZE	2048
 

@@ -764,6 +765,8 @@ static int serial_hsu_startup(struct uart_port *port)
 		container_of(port, struct uart_hsu_port, port);
 	unsigned long flags;
 
+	pm_runtime_get_sync(up->dev);
+
 	/*
 	 * Clear the FIFO buffers and disable them.
 	 * (they will be reenabled in set_termios())

@@ -871,6 +874,8 @@ static void serial_hsu_shutdown(struct uart_port *port)
 				  UART_FCR_CLEAR_RCVR |
 				  UART_FCR_CLEAR_XMIT);
 	serial_out(up, UART_FCR, 0);
+
+	pm_runtime_put(up->dev);
 }
 
 static void

@@ -1249,6 +1254,39 @@ static int serial_hsu_resume(struct pci_dev *pdev)
 #define serial_hsu_resume	NULL
 #endif
 
+#ifdef CONFIG_PM_RUNTIME
+static int serial_hsu_runtime_idle(struct device *dev)
+{
+	int err;
+
+	err = pm_schedule_suspend(dev, 500);
+	if (err)
+		return -EBUSY;
+
+	return 0;
+}
+
+static int serial_hsu_runtime_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static int serial_hsu_runtime_resume(struct device *dev)
+{
+	return 0;
+}
+#else
+#define serial_hsu_runtime_idle		NULL
+#define serial_hsu_runtime_suspend	NULL
+#define serial_hsu_runtime_resume	NULL
+#endif
+
+static const struct dev_pm_ops serial_hsu_pm_ops = {
+	.runtime_suspend = serial_hsu_runtime_suspend,
+	.runtime_resume = serial_hsu_runtime_resume,
+	.runtime_idle = serial_hsu_runtime_idle,
+};
+
 /* temp global pointer before we settle down on using one or four PCI dev */
 static struct hsu_port *phsu;
 

@@ -1315,6 +1353,9 @@ static int serial_hsu_probe(struct pci_dev *pdev,
 		pci_set_drvdata(pdev, uport);
 	}
 
+	pm_runtime_put_noidle(&pdev->dev);
+	pm_runtime_allow(&pdev->dev);
+
 	return 0;
 
 err_disable:

@@ -1411,6 +1452,9 @@ static void serial_hsu_remove(struct pci_dev *pdev)
 	if (!priv)
 		return;
 
+	pm_runtime_forbid(&pdev->dev);
+	pm_runtime_get_noresume(&pdev->dev);
+
 	/* For port 0/1/2, priv is the address of uart_hsu_port */
 	if (pdev->device != 0x081E) {
 		up = priv;

@@ -1438,6 +1482,9 @@ static struct pci_driver hsu_pci_driver = {
 	.remove =	__devexit_p(serial_hsu_remove),
 	.suspend =	serial_hsu_suspend,
 	.resume	=	serial_hsu_resume,
+	.driver = {
+		.pm = &serial_hsu_pm_ops,
+	},
 };
 
 static int __init hsu_pci_init(void)

index 8a50e4e..ed42908 100644
@@ -21,7 +21,6 @@
  *	Mostly done:	ioctls for setting modes/timing
  *	Partly done:	hooks so you can pull off frames to non tty devs
  *	Restart DLCI 0 when it closes ?
- *	Test basic encoding
  *	Improve the tx engine
  *	Resolve tx side locking by adding a queue_head and routing
  *		all control traffic via it

index ed42908..8d7766b 100644
@@ -2003,6 +2003,7 @@ void gsm_cleanup_mux(struct gsm_mux *gsm)
 	int i;
 	struct gsm_dlci *dlci = gsm->dlci[0];
 	struct gsm_msg *txq;
+	struct gsm_control *gc;
 
 	gsm->dead = 1;
 

@@ -2016,6 +2017,13 @@ void gsm_cleanup_mux(struct gsm_mux *gsm)
 	spin_unlock(&gsm_mux_lock);
 	WARN_ON(i == MAX_MUX);
 
+	/* In theory disconnecting DLCI 0 is sufficient but for some
+	   modems this is apparently not the case. */
+	if (dlci) {
+		gc = gsm_control_send(gsm, CMD_CLD, NULL, 0);
+		if (gc)
+			gsm_control_wait(gsm, gc);
+	}
 	del_timer_sync(&gsm->t2_timer);
 	/* Now we are sure T2 has stopped */
 	if (dlci) {

index a764bf9..c8f9868 100644
@@ -207,7 +207,7 @@ static void serial_m3110_con_write(struct console *co,
 	uart_console_write(&pmax->port, s, count, serial_m3110_con_putchar);
 
 	if (!test_and_set_bit(CON_TX_NEEDED, &pmax->uart_flags))
-		wake_up_process(pmax->main_thread);
+		wake_up(&pmax->wq);
 }
 
 static int __init

@@ -301,6 +301,7 @@ static void send_circ_buf(struct uart_max3110 *max,
 			}
 
 			/* Fail to send msg to console is not very critical */
+
 			ret = max3110_write_then_read(max, obuf, ibuf, blen, 0);
 			if (ret)
 				pr_warning(PR_FMT "%s(): get err msg %d\n",

@@ -349,7 +350,7 @@ static void serial_m3110_start_tx(struct uart_port *port)
 		container_of(port, struct uart_max3110, port);
 
 	if (!test_and_set_bit(UART_TX_NEEDED, &max->uart_flags))
-		wake_up_process(max->main_thread);
+		wake_up(&max->wq);
 }
 
 static void receive_chars(struct uart_max3110 *max, unsigned char *str, int len)

@@ -424,7 +425,8 @@ static int max3110_main_thread(void *_max)
 	pr_info(PR_FMT "start main thread\n");
 
 	do {
-		wait_event_interruptible(*wq, max->uart_flags || kthread_should_stop());
+		wait_event_interruptible(*wq,
+				max->uart_flags || kthread_should_stop());
 
 		mutex_lock(&max->thread_mutex);
 

@@ -452,8 +454,9 @@ static irqreturn_t serial_m3110_irq(int irq, void *dev_id)
 
 	/* max3110's irq is a falling edge, not level triggered,
 	 * so no need to disable the irq */
+
 	if (!test_and_set_bit(BIT_IRQ_PENDING, &max->uart_flags))
-		wake_up_process(max->main_thread);
+		wake_up(&max->wq);
 
 	return IRQ_HANDLED;
 }

index 7000e74..b8da1b9 100644
@@ -14,6 +14,8 @@
 
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/scatterlist.h>
 #include <linux/sfi.h>
 #include <linux/intel_pmic_gpio.h>
 #include <linux/spi/spi.h>

@@ -392,6 +394,7 @@ static void __init *max3111_platform_data(void *info)
 	struct spi_board_info *spi_info = info;
 	int intr = get_gpio_by_name("max3111_int");
 
+	spi_info->mode = SPI_MODE_0;
 	if (intr == -1)
 		return NULL;
 	spi_info->irq = intr + MRST_IRQ_OFFSET;

index c8f9868..42aa439 100644
@@ -27,6 +27,10 @@
  *    interrupt for a low speed UART device
  */
 
+#ifdef CONFIG_MAGIC_SYSRQ
+#define SUPPORT_SYSRQ
+#endif
+
 #include <linux/module.h>
 #include <linux/ioport.h>
 #include <linux/irq.h>

@@ -73,9 +77,9 @@ struct uart_max3110 {
 /* global data structure, may need be removed */
 static struct uart_max3110 *pmax;
 
-static void receive_chars(struct uart_max3110 *max,
-				unsigned char *str, int len);
-static int max3110_read_multi(struct uart_max3110 *max, u8 *buf);
+static int receive_chars(struct uart_max3110 *max,
+				unsigned short *str, int len);
+static int max3110_read_multi(struct uart_max3110 *max);
 static void max3110_con_receive(struct uart_max3110 *max);
 
 static int max3110_write_then_read(struct uart_max3110 *max,

@@ -108,7 +112,6 @@ static int max3110_out(struct uart_max3110 *max, const u16 out)
 {
 	void *buf;
 	u16 *obuf, *ibuf;
-	u8  ch;
 	int ret;
 
 	buf = kzalloc(8, GFP_KERNEL | GFP_DMA);

@@ -125,11 +128,7 @@ static int max3110_out(struct uart_max3110 *max, const u16 out)
 		goto exit;
 	}
 
-	/* If some valid data is read back */
-	if (*ibuf & MAX3110_READ_DATA_AVAILABLE) {
-		ch = *ibuf & 0xff;
-		receive_chars(max, &ch, 1);
-	}
+	receive_chars(max, ibuf, 1);
 
 exit:
 	kfree(buf);

@@ -142,12 +141,11 @@ exit:
  *
  * Return how many valide bytes are read back
  */
-static int max3110_read_multi(struct uart_max3110 *max, u8 *rxbuf)
+static int max3110_read_multi(struct uart_max3110 *max)
 {
 	void *buf;
 	u16 *obuf, *ibuf;
-	u8 *pbuf, valid_str[M3110_RX_FIFO_DEPTH];
-	int i, j, blen;
+	int ret, blen;
 
 	blen = M3110_RX_FIFO_DEPTH * sizeof(u16);
 	buf = kzalloc(blen * 2, GFP_KERNEL | GFP_DMA);

@@ -165,19 +163,10 @@ static int max3110_read_multi(struct uart_max3110 *max, u8 *rxbuf)
 		return 0;
 	}
 
-	/* If caller doesn't provide a buffer, then handle received char */
-	pbuf = rxbuf ? rxbuf : valid_str;
-
-	for (i = 0, j = 0; i < M3110_RX_FIFO_DEPTH; i++) {
-		if (ibuf[i] & MAX3110_READ_DATA_AVAILABLE)
-			pbuf[j++] = ibuf[i] & 0xff;
-	}
-
-	if (j && (pbuf == valid_str))
-		receive_chars(max, valid_str, j);
+	ret = receive_chars(max, ibuf, M3110_RX_FIFO_DEPTH);
 
 	kfree(buf);
-	return j;
+	return ret;
 }
 
 static void serial_m3110_con_putchar(struct uart_port *port, int ch)

@@ -276,8 +265,7 @@ static void send_circ_buf(struct uart_max3110 *max,
 {
 	void *buf;
 	u16 *obuf, *ibuf;
-	u8 valid_str[WORDS_PER_XFER];
-	int i, j, len, blen, dma_size, left, ret = 0;
+	int i, len, blen, dma_size, left, ret = 0;
 
 
 	dma_size = WORDS_PER_XFER * sizeof(u16) * 2;

@@ -307,13 +295,7 @@ static void send_circ_buf(struct uart_max3110 *max,
 				pr_warning(PR_FMT "%s(): get err msg %d\n",
 						__func__, ret);
 
-			for (i = 0, j = 0; i < len; i++) {
-				if (ibuf[i] & MAX3110_READ_DATA_AVAILABLE)
-					valid_str[j++] = ibuf[i] & 0xff;
-			}
-
-			if (j)
-				receive_chars(max, valid_str, j);
+			receive_chars(max, ibuf, len);
 
 			max->port.icount.tx += len;
 			left -= len;

@@ -353,30 +335,48 @@ static void serial_m3110_start_tx(struct uart_port *port)
 		wake_up(&max->wq);
 }
 
-static void receive_chars(struct uart_max3110 *max, unsigned char *str, int len)
+static int
+receive_chars(struct uart_max3110 *max, unsigned short *str, int len)
 {
 	struct uart_port *port = &max->port;
 	struct tty_struct *tty;
-	int usable;
+	char buf[M3110_RX_FIFO_DEPTH];
+	int r, w, usable;
 
 	/* If uart is not opened, just return */
 	if (!port->state)
-		return;
+		return 0;
 
 	tty = port->state->port.tty;
 	if (!tty)
-		return;
+		return 0;
+
+	for (r = 0, w = 0; r < len; r++) {
+		if (str[r] & MAX3110_BREAK &&
+		    uart_handle_break(port))
+			continue;
+
+		if (str[r] & MAX3110_READ_DATA_AVAILABLE) {
+			if (uart_handle_sysrq_char(port, str[r] & 0xff))
+				continue;
+
+			buf[w++] = str[r] & 0xff;
+		}
+	}
 
-	while (len) {
-		usable = tty_buffer_request_room(tty, len);
+	if (!w)
+		return 0;
+
+	for (r = 0; w; r += usable, w -= usable) {
+		usable = tty_buffer_request_room(tty, w);
 		if (usable) {
-			tty_insert_flip_string(tty, str, usable);
-			str += usable;
+			tty_insert_flip_string(tty, buf + r, usable);
 			port->icount.rx += usable;
 		}
-		len -= usable;
 	}
 	tty_flip_buffer_push(tty);
+
+	return r;
 }
 
 /*

@@ -391,28 +391,15 @@ static void receive_chars(struct uart_max3110 *max, unsigned char *str, int len)
  */
 static void max3110_con_receive(struct uart_max3110 *max)
 {
-	int loop = 1, num, total = 0;
-	u8 recv_buf[512], *pbuf;
+	int loop = 1, num;
 
-	pbuf = recv_buf;
 	do {
-		num = max3110_read_multi(max, pbuf);
+		num = max3110_read_multi(max);
 
 		if (num) {
 			loop = 5;
-			pbuf += num;
-			total += num;
-
-			if (total >= 504) {
-				receive_chars(max, recv_buf, total);
-				pbuf = recv_buf;
-				total = 0;
-			}
 		}
 	} while (--loop);
-
-	if (total)
-		receive_chars(max, recv_buf, total);
 }
 
 static int max3110_main_thread(void *_max)

index c37ea48..35af073 100644
@@ -7,6 +7,7 @@
 /* status bits for all 4 MAX3110 operate modes */
 #define MAX3110_READ_DATA_AVAILABLE	(1 << 15)
 #define MAX3110_WRITE_BUF_EMPTY		(1 << 14)
+#define MAX3110_BREAK			(1 << 10)
 
 #define WC_TAG			(3 << 14)
 #define RC_TAG			(1 << 14)

index 42aa439..1aa2c3c 100644
@@ -347,7 +347,7 @@ receive_chars(struct uart_max3110 *max, unsigned short *str, int len)
 	if (!port->state)
 		return 0;
 
-	tty = port->state->port.tty;
+	tty = tty_port_tty_get(&port->state->port);
 	if (!tty)
 		return 0;
 

@@ -364,8 +364,10 @@ receive_chars(struct uart_max3110 *max, unsigned short *str, int len)
 		}
 	}
 
-	if (!w)
+	if (!w) {
+		tty_kref_put(tty);
 		return 0;
+	}
 
 	for (r = 0; w; r += usable, w -= usable) {
 		usable = tty_buffer_request_room(tty, w);

@@ -375,6 +377,7 @@ receive_chars(struct uart_max3110 *max, unsigned short *str, int len)
 		}
 	}
 	tty_flip_buffer_push(tty);
+	tty_kref_put(tty);
 
 	return r;
 }