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

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

[Vitaly Wool]

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 <vitalywool@gmail.com>

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);

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

[Pierre Ossman]

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

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

[Vitaly Wool]

On 11/26/06, Pierre Ossman <drzeus-mmc@drzeus.cx> 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

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

[Pierre Ossman]

Vitaly Wool wrote:
> On 11/26/06, Pierre Ossman <drzeus-mmc@drzeus.cx> 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