[PATCH] 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. Signed-off-by: Rune Torgersen <[EMAIL PROTECTED]> diff --git a/drivers/serial/cpm_uart/cpm_uart_core.c b/drivers/serial/cpm_uart/cpm_uart_core.c index fb93403..79c109d 100755 --- a/drivers/serial/cpm_uart/cpm_uart_core.c +++ b/drivers/serial/cpm_uart/cpm_uart_core.c @@ -1214,7 +1214,9 @@ 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; + spin_lock_irqsave(&pinfo->port.lock, flags); /* Get the address of the host memory buffer. */ bdp = pinfo->tx_cur; @@ -1282,6 +1284,8 @@ static void cpm_uart_console_write(struct console *co, const char *s, ; pinfo->tx_cur = bdp; + + spin_unlock_irqrestore(&pinfo->port.lock, flags); } ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
[PATCH] 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]>
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);
+ }
}
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Re: [PATCH] Fix cpm uart corruption with PREEMPT_RT
On Tue, May 20, 2008 at 02:28:16PM -0500, Rune Torgersen wrote:
> 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.
>
> Signed-off-by: Rune Torgersen <[EMAIL PROTECTED]>
>
> diff --git a/drivers/serial/cpm_uart/cpm_uart_core.c
> b/drivers/serial/cpm_uart/cpm_uart_core.c
> index fb93403..79c109d 100755
> --- a/drivers/serial/cpm_uart/cpm_uart_core.c
> +++ b/drivers/serial/cpm_uart/cpm_uart_core.c
> @@ -1214,7 +1214,9 @@ 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;
>
> + spin_lock_irqsave(&pinfo->port.lock, flags);
> /* Get the address of the host memory buffer.
>*/
> bdp = pinfo->tx_cur;
> @@ -1282,6 +1284,8 @@ static void cpm_uart_console_write(struct console *co,
> const char *s,
> ;
>
> pinfo->tx_cur = bdp;
> +
> + spin_unlock_irqrestore(&pinfo->port.lock, flags);
> }
We should bypass the lock when oops_in_progress is set, something like:
diff --git a/drivers/serial/cpm_uart/cpm_uart_core.c
b/drivers/serial/cpm_uart/cpm_uart_core.c
index a19dc7e..bc45f8a 100644
--- a/drivers/serial/cpm_uart/cpm_uart_core.c
+++ b/drivers/serial/cpm_uart/cpm_uart_core.c
@@ -1178,6 +1178,14 @@ 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.
*/
@@ -1239,8 +1247,13 @@ 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);
+ }
+}
static int __init cpm_uart_console_setup(struct console *co, char *options)
{
-Scott
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RE: [PATCH] Fix cpm uart corruption with PREEMPT_RT
Scott Wood wrote: > On Tue, May 20, 2008 at 02:28:16PM -0500, Rune Torgersen wrote: >> 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. >> > > We should bypass the lock when oops_in_progress is set, something > like: > Ok, will respin. ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] Fix cpm uart corruption with PREEMPT_RT
Rune Torgersen wrote: 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]> Acked-by: Scott Wood <[EMAIL PROTECTED]> -Scott ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] Fix cpm uart corruption with PREEMPT_RT
On May 20, 2008, at 2:39 PM, Rune Torgersen wrote: 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]> applied. - k ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
