Re: [PATCH] mmc: blk: add emmc cache flush in shutdown callback

[Jaehoon Chung <jh80.chung@samsung.com>]

Hi,

On 07/14/2014 06:34 PM, Yunpeng Gao wrote:
> If eMMC Cache feature enabled, we'd better flush
> eMMC cache in the shutdown callback. Otherwise
> data corruption issue may be observed.

I knew mmc_flush_cache() is called into mmc_shutdown() (driver/mmc/core/mmc.c)
Which data corruption is occurred? Could you explain more?

Best Regards,
Jaehoon Chung 

> 
> Signed-off-by: Yunpeng Gao <yunpeng.gao@intel.com>
> ---
>  drivers/mmc/card/block.c |    4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index 452782b..8a4010e 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -2509,6 +2509,10 @@ static int _mmc_blk_suspend(struct mmc_card *card)
>  static void mmc_blk_shutdown(struct mmc_card *card)
>  {
>  	_mmc_blk_suspend(card);
> +
> +	mmc_claim_host(card->host);
> +	mmc_flush_cache(card);
> +	mmc_release_host(card->host);
>  }
>  
>  #ifdef CONFIG_PM
>