From: runet@innovsys•com (Rune Torgersen)
To: <linuxppc-dev@ozlabs•org>
Subject: [PATCH] Fix cpm uart corruption with PREEMPT_RT
Date: Tue, 20 May 2008 14:39:17 -0500 (CDT) [thread overview]
Message-ID: <20080520193917.C7ED15AF22@innovsys.com> (raw)
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 <runet@innovsys•com>
diff --git a/drivers/serial/cpm_uart/cpm_uart_core.c b/drivers/serial/cpm_uart/cpm_uart_core.c
index fb93403..11bee62 100755
--- a/drivers/serial/cpm_uart/cpm_uart_core.c
+++ b/drivers/serial/cpm_uart/cpm_uart_core.c
@@ -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);
+ }
}
next reply other threads:[~2008-05-20 19:38 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-20 19:39 Rune Torgersen [this message]
2008-05-20 19:42 ` [PATCH] Fix cpm uart corruption with PREEMPT_RT Scott Wood
2008-07-01 5:28 ` Kumar Gala
-- strict thread matches above, loose matches on Subject: below --
2008-05-20 19:28 Rune Torgersen
2008-05-20 19:33 ` Scott Wood
2008-05-20 19:35 ` Rune Torgersen
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