2006-11-23 15:42:18

by Vitaly Wool

Subject: [PATCH] fix "prev->state: 2 != TASK_RUNNING??" problem on SD/MMC card removal

Hello Pierre,

currently on SD/MMC card removal the system exhibits the following message (the platform is ARM Versatile):

prev->state: 2 != TASK_RUNNING??
mmcqd/762[CPU#0]: BUG in __schedule at linux-2.6/kernel/sched.c:3826

The patch inlined below fixes this problem.

drivers/mmc/mmc_queue.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

Signed-off-by: Vitaly Wool <[email protected]>

Index: linux-2.6.18/drivers/mmc/mmc_queue.c
===================================================================
--- linux-2.6.18.orig/drivers/mmc/mmc_queue.c
+++ linux-2.6.18/drivers/mmc/mmc_queue.c
@@ -84,8 +84,10 @@ static int mmc_queue_thread(void *d)
spin_unlock_irq(q->queue_lock);

if (!req) {
- if (mq->flags & MMC_QUEUE_EXIT)
+ if (mq->flags & MMC_QUEUE_EXIT) {
+ set_current_state(TASK_RUNNING);
break;
+ }
up(&mq->thread_sem);
schedule();
down(&mq->thread_sem);

2006-11-26 20:25:13

by Pierre Ossman

Subject: Re: [PATCH] fix "prev->state: 2 != TASK_RUNNING??" problem on SD/MMC card removal

Vitaly Wool wrote:
> Hello Pierre,
>
> currently on SD/MMC card removal the system exhibits the following message (the platform is ARM Versatile):
>
> prev->state: 2 != TASK_RUNNING??
> mmcqd/762[CPU#0]: BUG in __schedule at linux-2.6/kernel/sched.c:3826
>

Hmm... I can't find any such requirement in HEAD, or 2.6.18. What kernel
are you running?

Rgds
--
-- Pierre Ossman

Linux kernel, MMC maintainer http://www.kernel.org
PulseAudio, core developer http://pulseaudio.org
rdesktop, core developer http://www.rdesktop.org

2006-11-27 09:13:25

by Vitaly Wool

Subject: Re: [PATCH] fix "prev->state: 2 != TASK_RUNNING??" problem on SD/MMC card removal

On 11/26/06, Pierre Ossman <[email protected]> wrote:
> Hmm... I can't find any such requirement in HEAD, or 2.6.18. What kernel
> are you running?

2.6.18 + -rt patches by Ingo.

Vitaly

2006-11-27 13:47:40

by Pierre Ossman

Subject: Re: [PATCH] fix "prev->state: 2 != TASK_RUNNING??" problem on SD/MMC card removal

Vitaly Wool wrote:
> On 11/26/06, Pierre Ossman <[email protected]> wrote:
>> Hmm... I can't find any such requirement in HEAD, or 2.6.18. What kernel
>> are you running?
>
> 2.6.18 + -rt patches by Ingo.
>

I guess the check is in the rt set somewhere then.

Anyway, the mmc queue thread has undergone some changes so your patch
needs a bit of a tweak. But I'll put it on my todo and make sure it gets
in during the next merge window.

Rgds
--
-- Pierre Ossman

Linux kernel, MMC maintainer http://www.kernel.org
PulseAudio, core developer http://pulseaudio.org
rdesktop, core developer http://www.rdesktop.org