Thanks a lot for the review and comments. This patch was derived from our old mmc driver code base, which was based on kernel 3.10 and did not implemented the mmc_shutdown() callback in mmc.c yet. So it added shutdown callback in drivers/mmc/card/block.c to fix data corruption issue observed at that time. Since flush eMMC cache in mmc_shutdown() callback is better than in mmc_blk_shutdown(), I think my patch is not needed for current upstream mmc driver any more. Please ignore it :-) Thanks. Regards, Yunpeng -----Original Message----- From: Jaehoon Chung [mailto:jh80.chung@xxxxxxxxxxx] Sent: Monday, July 14, 2014 5:51 PM To: Gao, Yunpeng; linux-mmc@xxxxxxxxxxxxxxx Subject: Re: [PATCH] mmc: blk: add emmc cache flush in shutdown callback 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@xxxxxxxxx> > --- > 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 > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
