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Fix cpm uart corruption with PREEMPT_RT

PATCH Applied Rune Torgersen 3 participants 3 messages May 20, 2008 – Jul 1, 2008

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Rune Torgersen

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PATCH 1/1 Fix cpm uart corruption with PREEMPT_RT

Fix CPM serial port corruption when running with CONFIG_PREEMPT_RT. Userland usage of console, and kernel printf's were stepping on each others toes. Also only take lock if not in an oops.

Signed-off-by Rune Torgersen <[email protected]>
drivers/serial/cpm_uart/cpm_uart_core.c +14 -0
index fb93403..11bee62 100755
@@ -1214,6 +1214,14 @@ static void cpm_uart_console_write(struct console *co, const char *s,
 	unsigned int i;
 	cbd_t __iomem *bdp, *bdbase;
 	unsigned char *cp;
+	unsigned long flags;
+	int nolock = oops_in_progress;
+
+	if (unlikely(nolock)) {
+		local_irq_save(flags);
+	} else {
+		spin_lock_irqsave(&pinfo->port.lock, flags);
+	}
 
 	/* Get the address of the host memory buffer.
 	 */

@@ -1282,6 +1290,12 @@ static void cpm_uart_console_write(struct console *co, const char *s,
 		;
 
 	pinfo->tx_cur = bdp;
+
+	if (unlikely(nolock)) {
+		local_irq_restore(flags);
+	} else {
+		spin_unlock_irqrestore(&pinfo->port.lock, flags);
+	}
 }