On Tue, 10 Oct 2023 at 17:33, Bean Huo beanhuo@iokpp.de wrote:
Hi Ulf,
thanks for your comments, I didn't quite get your points:
On Tue, 2023-10-10 at 16:20 +0200, Ulf Hansson wrote:
@@ -2381,8 +2381,11 @@ enum mmc_issued mmc_blk_mq_issue_rq(struct mmc_queue *mq, struct request *req) } ret = mmc_blk_cqe_issue_flush(mq, req); break;
case REQ_OP_READ: case REQ_OP_WRITE:
if (mmc_card_broken_cache_flush(card) &&!card->written_flag)
It looks superfluous to me to check mmc_card_broken_cache_flush() and !card->written_flag. Just set the card->written_flag unconditionally.
what did you mean "Just set the card->written_flag unconditionally."? This means I just need to check card->written_flag and set card-
written_flag to true and false in the case
MMC_QUIRK_BROKEN_CACHE_FLUSH? or don't need to call mmc_card_broken_cache_flush()?
I mean skip the checks above and just do the assignment below.
card->written_flag = true;fallthrough;case REQ_OP_READ: if (host->cqe_enabled) ret = mmc_blk_cqe_issue_rw_rq(mq,req); else diff --git a/drivers/mmc/core/card.h b/drivers/mmc/core/card.h index 4edf9057fa79..b7754a1b8d97 100644 --- a/drivers/mmc/core/card.h +++ b/drivers/mmc/core/card.h @@ -280,4 +280,8 @@ static inline int mmc_card_broken_sd_cache(const struct mmc_card *c) return c->quirks & MMC_QUIRK_BROKEN_SD_CACHE; }
+static inline int mmc_card_broken_cache_flush(const struct mmc_card *c) +{
return c->quirks & MMC_QUIRK_BROKEN_CACHE_FLUSH;+} #endif diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 89cd48fcec79..47896c32086e 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -1929,6 +1929,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, if (!oldcard) host->card = card;
card->written_flag = false;How about doing this after a successful flush operation instead? In other words in _mmc_flush_cache().
Here initializes flag and the patch is intenting to eliminate the cache flush command before writing. what do you mean adding in mmc_flush_cache()?
mmc_init_card() is called while initializing and re-initializing the card. So, it certainly works to reset the flag from here.
However, _mmc_flush_cache() is called before powering off the card, which then would work similarly to the above, but also gets called for REQ_OP_FLUSH. Wouldn't that mean that we may be able to skip some unnecessary/troublesome cache flush requests if we would reset the flag from mmc_flush_cache(), rather than from mmc_init_card()?
Kind regards Uffe