Re: [patch 4/4] mtd/nand: fix multi-chip suspend problem

[Artem Bityutskiy <dedekind1@gmail.com>]

On Tue, 2009-11-17 at 14:45 -0800, akpm@linux-foundation.org wrote:
> From: Li Yang <leoli@freescale.com>
> 
> Symptom:
> device_suspend(): mtd_cls_suspend+0x0/0x58 returns -11
> PM: Device mtd14 failed to suspend: error -11
> PM: Some devices failed to suspend
> 
> This patch enables other chips to be suspended if the active chip of
> the controller has been suspended.
> 
> Signed-off-by: Jin Qing <b24347@freescale.com>
> Signed-off-by: Li Yang <leoli@freescale.com>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
> 
>  drivers/mtd/nand/nand_base.c |   14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 
> diff -puN drivers/mtd/nand/nand_base.c~mtd-nand-fix-multi-chip-suspend-problem drivers/mtd/nand/nand_base.c
> --- a/drivers/mtd/nand/nand_base.c~mtd-nand-fix-multi-chip-suspend-problem
> +++ a/drivers/mtd/nand/nand_base.c
> @@ -697,10 +697,16 @@ nand_get_device(struct nand_chip *chip, 
>  		spin_unlock(lock);
>  		return 0;
>  	}
> -	if (new_state == FL_PM_SUSPENDED) {
> -		spin_unlock(lock);
> -		return (chip->state == FL_PM_SUSPENDED) ? 0 : -EAGAIN;
> -	}
> +	if (new_state == FL_PM_SUSPENDED)
> +		if (chip->controller->active->state == FL_PM_SUSPENDED) {
> +			chip->state = FL_PM_SUSPENDED;
> +			spin_unlock(lock);
> +			return 0;
> +		} else {
> +			spin_unlock(lock);
> +			return -EAGAIN;
> +		}
> +
>  	set_current_state(TASK_UNINTERRUPTIBLE);
>  	add_wait_queue(wq, &wait);
>  	spin_unlock(lock);

This patch casing the following gcc warning:

drivers/mtd/nand/nand_base.c: In function ‘nand_get_device’:
drivers/mtd/nand/nand_base.c:700: warning: suggest explicit braces to
avoid ambiguous ‘else’

-- 
Best Regards,
Artem Bityutskiy (Артём Битюцкий)