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Date: Mon, 7 Apr 2008 16:15:55 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Subject: Re: [PATCH] mtd/chips: add missing set_current_state() to
	cfi_{amdstd,staa}_sync()
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On Thu, 03 Apr 2008 21:38:23 +0200
Dmitry Adamushko <dmitry.adamushko@gmail.com> wrote:

> From: Dmitry Adamushko <dmitry.adamushko@gmail.com>
> Subject: [mtd/chips] add missing set_current_state() to cfi_{amdstd,staa}_sync()
> 
> cfi_amdstd_sync() and cfi_staa_sync() call schedule() without changing
> task's state appropriately.
> 
> In case of e.g. chip->state == FL_ERASING, cfi_*_sync() will be busy-looping
> either redundantly for a fixed interval of time (for SCHED_NORMAL tasks) or
> possibly endlessly (for RT tasks and UP).
> 
> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
> 
> ---
> 
> diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
> index d072e87..458d477 100644
> --- a/drivers/mtd/chips/cfi_cmdset_0002.c
> +++ b/drivers/mtd/chips/cfi_cmdset_0002.c
> @@ -1763,6 +1763,7 @@ static void cfi_amdstd_sync (struct mtd_info *mtd)
>  
>  		default:
>  			/* Not an idle state */
> +			set_current_state(TASK_UNINTERRUPTIBLE);
>  			add_wait_queue(&chip->wq, &wait);
>  
>  			spin_unlock(chip->mutex);
> diff --git a/drivers/mtd/chips/cfi_cmdset_0020.c b/drivers/mtd/chips/cfi_cmdset_0020.c
> index b344ff8..492e2ab 100644
> --- a/drivers/mtd/chips/cfi_cmdset_0020.c
> +++ b/drivers/mtd/chips/cfi_cmdset_0020.c
> @@ -1015,6 +1015,7 @@ static void cfi_staa_sync (struct mtd_info *mtd)
>  
>  		default:
>  			/* Not an idle state */
> +			set_current_state(TASK_UNINTERRUPTIBLE);
>  			add_wait_queue(&chip->wq, &wait);
>  
>  			spin_unlock_bh(chip->mutex);

The change certainly looks correct.  Has it been runtime tested?

Thanks.