MOXA: mxser_new lockup

@@ -2352,27 +2352,43 @@
 					if (iir == MOXA_MUST_IIR_GDA ||
 					    iir == MOXA_MUST_IIR_RDA ||
 					    iir == MOXA_MUST_IIR_RTO ||
-					    iir == MOXA_MUST_IIR_LSR)
+					    iir == MOXA_MUST_IIR_LSR) {
+						spin_unlock(&port->slock);
 						mxser_receive_chars(port,
 								&status);
+						spin_lock(&port->slock);
+					}
 
 				} else {
 					status &= port->read_status_mask;
-					if (status & UART_LSR_DR)
+					if (status & UART_LSR_DR) {
+						spin_unlock(&port->slock);
 						mxser_receive_chars(port,
 								&status);
+						spin_lock(&port->slock);
+					}
 				}
 				msr = inb(port->ioaddr + UART_MSR);
-				if (msr & UART_MSR_ANY_DELTA)
+				if (msr & UART_MSR_ANY_DELTA) {
+					spin_unlock(&port->slock);
 					mxser_check_modem_status(port, msr);
+					spin_lock(&port->slock);
+				}
 
 				if (port->board->chip_flag) {
 					if (iir == 0x02 && (status &
-								UART_LSR_THRE))
+							UART_LSR_THRE)) {
+						spin_unlock(&port->slock);
+						
 						mxser_transmit_chars(port);
+						spin_lock(&port->slock);
+					}
 				} else {
-					if (status & UART_LSR_THRE)
+					if (status & UART_LSR_THRE) {
+						spin_unlock(&port->slock);
 						mxser_transmit_chars(port);
+						spin_lock(&port->slock);
+					}
 				}
 			} while (int_cnt++ < MXSER_ISR_PASS_LIMIT);
 			spin_unlock(&port->slock);

index 6362e78..0086b73 100644
@@ -85,6 +85,16 @@
 #define MXSER_HIGHBAUD	1
 #define MXSER_HAS2	2
 
+/* if we are in interrupt, lock is held by ISR, don't acquire it again! */
+#define mx_lock(info, flags) do {				\
+	if (!in_interrupt())					\
+		spin_lock_irqsave(&(info)->slock, flags);	\
+} while (0)
+#define mx_unlock(info, flags) do {				\
+	if (!in_interrupt())					\
+		spin_unlock_irqrestore(&(info)->slock, flags);	\
+} while (0)
+
 /* This is only for PCI */
 static const struct {
 	int type;

@@ -415,16 +425,16 @@ static int mxser_block_til_ready(struct tty_struct *tty, struct file *filp,
 	retval = 0;
 	add_wait_queue(&port->open_wait, &wait);
 
-	spin_lock_irqsave(&port->slock, flags);
+	mx_lock(port, flags);
 	if (!tty_hung_up_p(filp))
 		port->count--;
-	spin_unlock_irqrestore(&port->slock, flags);
+	mx_unlock(port, flags);
 	port->blocked_open++;
 	while (1) {
-		spin_lock_irqsave(&port->slock, flags);
+		mx_lock(port, flags);
 		outb(inb(port->ioaddr + UART_MCR) |
 			UART_MCR_DTR | UART_MCR_RTS, port->ioaddr + UART_MCR);
-		spin_unlock_irqrestore(&port->slock, flags);
+		mx_unlock(port, flags);
 		set_current_state(TASK_INTERRUPTIBLE);
 		if (tty_hung_up_p(filp) || !(port->flags & ASYNC_INITIALIZED)) {
 			if (port->flags & ASYNC_HUP_NOTIFY)

@@ -765,11 +775,11 @@ static int mxser_startup(struct mxser_port *info)
 	if (!page)
 		return -ENOMEM;
 
-	spin_lock_irqsave(&info->slock, flags);
+	mx_lock(info, flags);
 
 	if (info->flags & ASYNC_INITIALIZED) {
 		free_page(page);
-		spin_unlock_irqrestore(&info->slock, flags);
+		mx_unlock(info, flags);
 		return 0;
 	}
 

@@ -777,7 +787,7 @@ static int mxser_startup(struct mxser_port *info)
 		if (info->tty)
 			set_bit(TTY_IO_ERROR, &info->tty->flags);
 		free_page(page);
-		spin_unlock_irqrestore(&info->slock, flags);
+		mx_unlock(info, flags);
 		return 0;
 	}
 	if (info->xmit_buf)

@@ -803,7 +813,7 @@ static int mxser_startup(struct mxser_port *info)
 	 * here.
 	 */
 	if (inb(info->ioaddr + UART_LSR) == 0xff) {
-		spin_unlock_irqrestore(&info->slock, flags);
+		mx_unlock(info, flags);
 		if (capable(CAP_SYS_ADMIN)) {
 			if (info->tty)
 				set_bit(TTY_IO_ERROR, &info->tty->flags);

@@ -853,7 +863,7 @@ static int mxser_startup(struct mxser_port *info)
 	 */
 	mxser_change_speed(info, NULL);
 	info->flags |= ASYNC_INITIALIZED;
-	spin_unlock_irqrestore(&info->slock, flags);
+	mx_unlock(info, flags);
 
 	return 0;
 }

@@ -869,7 +879,7 @@ static void mxser_shutdown(struct mxser_port *info)
 	if (!(info->flags & ASYNC_INITIALIZED))
 		return;
 
-	spin_lock_irqsave(&info->slock, flags);
+	mx_lock(info, flags);
 
 	/*
 	 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq

@@ -912,7 +922,7 @@ static void mxser_shutdown(struct mxser_port *info)
 	if (info->board->chip_flag)
 		SET_MOXA_MUST_NO_SOFTWARE_FLOW_CONTROL(info->ioaddr);
 
-	spin_unlock_irqrestore(&info->slock, flags);
+	mx_unlock(info, flags);
 }
 
 /*

@@ -941,9 +951,9 @@ static int mxser_open(struct tty_struct *tty, struct file *filp)
 	/*
 	 * Start up serial port
 	 */
-	spin_lock_irqsave(&info->slock, flags);
+	mx_lock(info, flags);
 	info->count++;
-	spin_unlock_irqrestore(&info->slock, flags);
+	mx_unlock(info, flags);
 	retval = mxser_startup(info);
 	if (retval)
 		return retval;

@@ -975,10 +985,10 @@ static void mxser_close(struct tty_struct *tty, struct file *filp)
 	if (!info)
 		return;
 
-	spin_lock_irqsave(&info->slock, flags);
+	mx_lock(info, flags);
 
 	if (tty_hung_up_p(filp)) {
-		spin_unlock_irqrestore(&info->slock, flags);
+		mx_unlock(info, flags);
 		return;
 	}
 	if ((tty->count == 1) && (info->count != 1)) {

@@ -999,11 +1009,11 @@ static void mxser_close(struct tty_struct *tty, struct file *filp)
 		info->count = 0;
 	}
 	if (info->count) {
-		spin_unlock_irqrestore(&info->slock, flags);
+		mx_unlock(info, flags);
 		return;
 	}
 	info->flags |= ASYNC_CLOSING;
-	spin_unlock_irqrestore(&info->slock, flags);
+	mx_unlock(info, flags);
 	/*
 	 * Save the termios structure, since this port may have
 	 * separate termios for callout and dialin.

@@ -1076,11 +1086,11 @@ static int mxser_write(struct tty_struct *tty, const unsigned char *buf, int cou
 			break;
 
 		memcpy(info->xmit_buf + info->xmit_head, buf, c);
-		spin_lock_irqsave(&info->slock, flags);
+		mx_lock(info, flags);
 		info->xmit_head = (info->xmit_head + c) &
 				  (SERIAL_XMIT_SIZE - 1);
 		info->xmit_cnt += c;
-		spin_unlock_irqrestore(&info->slock, flags);
+		mx_unlock(info, flags);
 
 		buf += c;
 		count -= c;

@@ -1091,12 +1101,12 @@ static int mxser_write(struct tty_struct *tty, const unsigned char *buf, int cou
 		if (!tty->hw_stopped ||
 				(info->type == PORT_16550A) ||
 				(info->board->chip_flag)) {
-			spin_lock_irqsave(&info->slock, flags);
+			mx_lock(info, flags);
 			outb(info->IER & ~UART_IER_THRI, info->ioaddr +
 					UART_IER);
 			info->IER |= UART_IER_THRI;
 			outb(info->IER, info->ioaddr + UART_IER);
-			spin_unlock_irqrestore(&info->slock, flags);
+			mx_unlock(info, flags);
 		}
 	}
 	return total;

@@ -1113,20 +1123,20 @@ static void mxser_put_char(struct tty_struct *tty, unsigned char ch)
 	if (info->xmit_cnt >= SERIAL_XMIT_SIZE - 1)
 		return;
 
-	spin_lock_irqsave(&info->slock, flags);
+	mx_lock(info, flags);
 	info->xmit_buf[info->xmit_head++] = ch;
 	info->xmit_head &= SERIAL_XMIT_SIZE - 1;
 	info->xmit_cnt++;
-	spin_unlock_irqrestore(&info->slock, flags);
+	mx_unlock(info, flags);
 	if (!tty->stopped) {
 		if (!tty->hw_stopped ||
 				(info->type == PORT_16550A) ||
 				info->board->chip_flag) {
-			spin_lock_irqsave(&info->slock, flags);
+			mx_lock(info, flags);
 			outb(info->IER & ~UART_IER_THRI, info->ioaddr + UART_IER);
 			info->IER |= UART_IER_THRI;
 			outb(info->IER, info->ioaddr + UART_IER);
-			spin_unlock_irqrestore(&info->slock, flags);
+			mx_unlock(info, flags);
 		}
 	}
 }

@@ -1146,13 +1156,13 @@ static void mxser_flush_chars(struct tty_struct *tty)
 			))
 		return;
 
-	spin_lock_irqsave(&info->slock, flags);
+	mx_lock(info, flags);
 
 	outb(info->IER & ~UART_IER_THRI, info->ioaddr + UART_IER);
 	info->IER |= UART_IER_THRI;
 	outb(info->IER, info->ioaddr + UART_IER);
 
-	spin_unlock_irqrestore(&info->slock, flags);
+	mx_unlock(info, flags);
 }
 
 static int mxser_write_room(struct tty_struct *tty)

@@ -1179,7 +1189,7 @@ static void mxser_flush_buffer(struct tty_struct *tty)
 	unsigned long flags;
 
 
-	spin_lock_irqsave(&info->slock, flags);
+	mx_lock(info, flags);
 	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
 
 	fcr = inb(info->ioaddr + UART_FCR);

@@ -1187,7 +1197,7 @@ static void mxser_flush_buffer(struct tty_struct *tty)
 		info->ioaddr + UART_FCR);
 	outb(fcr, info->ioaddr + UART_FCR);
 
-	spin_unlock_irqrestore(&info->slock, flags);
+	mx_unlock(info, flags);
 
 	tty_wakeup(tty);
 }

@@ -1268,9 +1278,9 @@ static int mxser_set_serial_info(struct mxser_port *info,
 
 	if (info->flags & ASYNC_INITIALIZED) {
 		if (flags != (info->flags & ASYNC_SPD_MASK)) {
-			spin_lock_irqsave(&info->slock, sl_flags);
+			mx_lock(info, sl_flags);
 			mxser_change_speed(info, NULL);
-			spin_unlock_irqrestore(&info->slock, sl_flags);
+			mx_unlock(info, sl_flags);
 		}
 	} else
 		retval = mxser_startup(info);

@@ -1295,9 +1305,9 @@ static int mxser_get_lsr_info(struct mxser_port *info,
 	unsigned int result;
 	unsigned long flags;
 
-	spin_lock_irqsave(&info->slock, flags);
+	mx_lock(info, flags);
 	status = inb(info->ioaddr + UART_LSR);
-	spin_unlock_irqrestore(&info->slock, flags);
+	mx_unlock(info, flags);
 	result = ((status & UART_LSR_TEMT) ? TIOCSER_TEMT : 0);
 	return put_user(result, value);
 }

@@ -1312,15 +1322,15 @@ static void mxser_send_break(struct mxser_port *info, int duration)
 	if (!info->ioaddr)
 		return;
 	set_current_state(TASK_INTERRUPTIBLE);
-	spin_lock_irqsave(&info->slock, flags);
+	mx_lock(info, flags);
 	outb(inb(info->ioaddr + UART_LCR) | UART_LCR_SBC,
 		info->ioaddr + UART_LCR);
-	spin_unlock_irqrestore(&info->slock, flags);
+	mx_unlock(info, flags);
 	schedule_timeout(duration);
-	spin_lock_irqsave(&info->slock, flags);
+	mx_lock(info, flags);
 	outb(inb(info->ioaddr + UART_LCR) & ~UART_LCR_SBC,
 		info->ioaddr + UART_LCR);
-	spin_unlock_irqrestore(&info->slock, flags);
+	mx_unlock(info, flags);
 }
 
 static int mxser_tiocmget(struct tty_struct *tty, struct file *file)

@@ -1337,11 +1347,11 @@ static int mxser_tiocmget(struct tty_struct *tty, struct file *file)
 
 	control = info->MCR;
 
-	spin_lock_irqsave(&info->slock, flags);
+	mx_lock(info, flags);
 	status = inb(info->ioaddr + UART_MSR);
 	if (status & UART_MSR_ANY_DELTA)
 		mxser_check_modem_status(info, status);
-	spin_unlock_irqrestore(&info->slock, flags);
+	mx_unlock(info, flags);
 	return ((control & UART_MCR_RTS) ? TIOCM_RTS : 0) |
 		    ((control & UART_MCR_DTR) ? TIOCM_DTR : 0) |
 		    ((status & UART_MSR_DCD) ? TIOCM_CAR : 0) |

@@ -1362,7 +1372,7 @@ static int mxser_tiocmset(struct tty_struct *tty, struct file *file,
 	if (test_bit(TTY_IO_ERROR, &tty->flags))
 		return -EIO;
 
-	spin_lock_irqsave(&info->slock, flags);
+	mx_lock(info, flags);
 
 	if (set & TIOCM_RTS)
 		info->MCR |= UART_MCR_RTS;

@@ -1375,7 +1385,7 @@ static int mxser_tiocmset(struct tty_struct *tty, struct file *file,
 		info->MCR &= ~UART_MCR_DTR;
 
 	outb(info->MCR, info->ioaddr + UART_MCR);
-	spin_unlock_irqrestore(&info->slock, flags);
+	mx_unlock(info, flags);
 	return 0;
 }
 

@@ -1706,9 +1716,9 @@ static int mxser_ioctl(struct tty_struct *tty, struct file *file,
 			info->tty->termios->c_cflag |= mxvar_baud_table1[i];
 
 		info->speed = speed;
-		spin_lock_irqsave(&info->slock, flags);
+		mx_lock(info, flags);
 		mxser_change_speed(info, NULL);
-		spin_unlock_irqrestore(&info->slock, flags);
+		mx_unlock(info, flags);
 
 		return 0;
 	} else if (cmd == MOXA_GET_SPECIAL_BAUD_RATE) {

@@ -1760,15 +1770,15 @@ static int mxser_ioctl(struct tty_struct *tty, struct file *file,
 	case TIOCMIWAIT: {
 		DECLARE_WAITQUEUE(wait, current);
 		int ret;
-		spin_lock_irqsave(&info->slock, flags);
+		mx_lock(info, flags);
 		cprev = info->icount;	/* note the counters on entry */
-		spin_unlock_irqrestore(&info->slock, flags);
+		mx_unlock(info, flags);
 
 		add_wait_queue(&info->delta_msr_wait, &wait);
 		while (1) {
-			spin_lock_irqsave(&info->slock, flags);
+			mx_lock(info, flags);
 			cnow = info->icount;	/* atomic copy */
-			spin_unlock_irqrestore(&info->slock, flags);
+			mx_unlock(info, flags);
 
 			set_current_state(TASK_INTERRUPTIBLE);
 			if (((arg & TIOCM_RNG) &&

@@ -1801,9 +1811,9 @@ static int mxser_ioctl(struct tty_struct *tty, struct file *file,
 	 *     RI where only 0->1 is counted.
 	 */
 	case TIOCGICOUNT:
-		spin_lock_irqsave(&info->slock, flags);
+		mx_lock(info, flags);
 		cnow = info->icount;
-		spin_unlock_irqrestore(&info->slock, flags);
+		mx_unlock(info, flags);
 		p_cuser = argp;
 		if (put_user(cnow.frame, &p_cuser->frame))
 			return -EFAULT;

@@ -1834,9 +1844,9 @@ static int mxser_ioctl(struct tty_struct *tty, struct file *file,
 		long baud;
 		if (get_user(baud, (long __user *)argp))
 			return -EFAULT;
-		spin_lock_irqsave(&info->slock, flags);
+		mx_lock(info, flags);
 		mxser_set_baud(info, baud);
-		spin_unlock_irqrestore(&info->slock, flags);
+		mx_unlock(info, flags);
 		return 0;
 	}
 	case MOXA_ASPP_GETBAUD:

@@ -1983,12 +1993,12 @@ static void mxser_stop(struct tty_struct *tty)
 	struct mxser_port *info = tty->driver_data;
 	unsigned long flags;
 
-	spin_lock_irqsave(&info->slock, flags);
+	mx_lock(info, flags);
 	if (info->IER & UART_IER_THRI) {
 		info->IER &= ~UART_IER_THRI;
 		outb(info->IER, info->ioaddr + UART_IER);
 	}
-	spin_unlock_irqrestore(&info->slock, flags);
+	mx_unlock(info, flags);
 }
 
 static void mxser_start(struct tty_struct *tty)

@@ -1996,13 +2006,13 @@ static void mxser_start(struct tty_struct *tty)
 	struct mxser_port *info = tty->driver_data;
 	unsigned long flags;
 
-	spin_lock_irqsave(&info->slock, flags);
+	mx_lock(info, flags);
 	if (info->xmit_cnt && info->xmit_buf) {
 		outb(info->IER & ~UART_IER_THRI, info->ioaddr + UART_IER);
 		info->IER |= UART_IER_THRI;
 		outb(info->IER, info->ioaddr + UART_IER);
 	}
-	spin_unlock_irqrestore(&info->slock, flags);
+	mx_unlock(info, flags);
 }
 
 static void mxser_set_termios(struct tty_struct *tty, struct ktermios *old_termios)

@@ -2013,9 +2023,9 @@ static void mxser_set_termios(struct tty_struct *tty, struct ktermios *old_termi
 	if ((tty->termios->c_cflag != old_termios->c_cflag) ||
 			(RELEVANT_IFLAG(tty->termios->c_iflag) != RELEVANT_IFLAG(old_termios->c_iflag))) {
 
-		spin_lock_irqsave(&info->slock, flags);
+		mx_lock(info, flags);
 		mxser_change_speed(info, old_termios);
-		spin_unlock_irqrestore(&info->slock, flags);
+		mx_unlock(info, flags);
 
 		if ((old_termios->c_cflag & CRTSCTS) &&
 				!(tty->termios->c_cflag & CRTSCTS)) {

@@ -2030,9 +2040,9 @@ static void mxser_set_termios(struct tty_struct *tty, struct ktermios *old_termi
 		tty->stopped = 0;
 
 		if (info->board->chip_flag) {
-			spin_lock_irqsave(&info->slock, flags);
+			mx_lock(info, flags);
 			DISABLE_MOXA_MUST_RX_SOFTWARE_FLOW_CONTROL(info->ioaddr);
-			spin_unlock_irqrestore(&info->slock, flags);
+			mx_unlock(info, flags);
 		}
 
 		mxser_start(tty);

@@ -2126,14 +2136,14 @@ static void mxser_rs_break(struct tty_struct *tty, int break_state)
 	struct mxser_port *info = tty->driver_data;
 	unsigned long flags;
 
-	spin_lock_irqsave(&info->slock, flags);
+	mx_lock(info, flags);
 	if (break_state == -1)
 		outb(inb(info->ioaddr + UART_LCR) | UART_LCR_SBC,
 			info->ioaddr + UART_LCR);
 	else
 		outb(inb(info->ioaddr + UART_LCR) & ~UART_LCR_SBC,
 			info->ioaddr + UART_LCR);
-	spin_unlock_irqrestore(&info->slock, flags);
+	mx_unlock(info, flags);
 }
 
 static void mxser_receive_chars(struct mxser_port *port, int *status)

index 0086b73..02b6141 100644
@@ -1767,43 +1767,23 @@ static int mxser_ioctl(struct tty_struct *tty, struct file *file,
 		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
 		 * Caller should use TIOCGICOUNT to see which one it was
 		 */
-	case TIOCMIWAIT: {
-		DECLARE_WAITQUEUE(wait, current);
-		int ret;
+	case TIOCMIWAIT:
 		mx_lock(info, flags);
-		cprev = info->icount;	/* note the counters on entry */
+		cnow = info->icount;	/* note the counters on entry */
 		mx_unlock(info, flags);
 
-		add_wait_queue(&info->delta_msr_wait, &wait);
-		while (1) {
+		wait_event_interruptible(info->delta_msr_wait, ({
+			cprev = cnow;
 			mx_lock(info, flags);
 			cnow = info->icount;	/* atomic copy */
 			mx_unlock(info, flags);
 
-			set_current_state(TASK_INTERRUPTIBLE);
-			if (((arg & TIOCM_RNG) &&
-					(cnow.rng != cprev.rng)) ||
-					((arg & TIOCM_DSR) &&
-					(cnow.dsr != cprev.dsr)) ||
-					((arg & TIOCM_CD) &&
-					(cnow.dcd != cprev.dcd)) ||
-					((arg & TIOCM_CTS) &&
-					(cnow.cts != cprev.cts))) {
-				ret = 0;
-				break;
-			}
-			/* see if a signal did it */
-			if (signal_pending(current)) {
-				ret = -ERESTARTSYS;
-				break;
-			}
-			cprev = cnow;
-		}
-		current->state = TASK_RUNNING;
-		remove_wait_queue(&info->delta_msr_wait, &wait);
+			((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
+			((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
+			((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
+			((arg & TIOCM_CTS) && (cnow.cts != cprev.cts));
+		}));
 		break;
-	}
-	/* NOTREACHED */
 	/*
 	 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
 	 * Return: write counters to the user passed counter struct