Re: [PATCH v4] mmc: Add quirk MMC_QUIRK_BROKEN_CACHE_FLUSH for Micron eMMC Q2J54A

Hi Ulf,

Any comments on this version?

Kind regards,

Beam

On 01.10.23 9:49 PM, Bean Huo wrote:

From: Bean Huo beanhuo@micron.com

Micron MTFC4GACAJCN eMMC supports cache but requires that flush cache operation be allowed only after a write has occurred. Otherwise, the cache flush command or subsequent commands will time out.

Signed-off-by: Bean Huo beanhuo@micron.com Signed-off-by: Rafael Beims rafael.beims@toradex.com Cc: stable@vger.kernel.org

---

Changelog:

v3--v4: 1. Add helper function for this quirk in drivers/mmc/core/card.h. 2. Set card->written_flag only for REQ_OP_WRITE. v2--v3: 1. Set card->written_flag in mmc_blk_mq_issue_rq(). v1--v2: 1. Add Rafael's test-tag, and Co-developed-by. 2. Check host->card whether NULL or not in __mmc_start_request() before asserting host->card->->quirks

---

drivers/mmc/core/block.c | 5 ++++- drivers/mmc/core/card.h | 4 ++++ drivers/mmc/core/mmc.c | 5 +++++ drivers/mmc/core/quirks.h | 7 ++++--- include/linux/mmc/card.h | 2 ++ 5 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c index 3a8f27c3e310..dfa67d9c80bb 100644 --- a/drivers/mmc/core/block.c +++ b/drivers/mmc/core/block.c @@ -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)
  

• 		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;
• return 0;

free_card: @@ -2081,6 +2083,9 @@ static int _mmc_flush_cache(struct mmc_host *host) { int err = 0;

• if (mmc_card_broken_cache_flush(host->card) && !host->card->written_flag)

• return err;
  

• if (_mmc_cache_enabled(host)) { err = mmc_switch(host->card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_FLUSH_CACHE, 1,

diff --git a/drivers/mmc/core/quirks.h b/drivers/mmc/core/quirks.h index 32b64b564fb1..5e68c8b4cdca 100644 --- a/drivers/mmc/core/quirks.h +++ b/drivers/mmc/core/quirks.h @@ -110,11 +110,12 @@ static const struct mmc_fixup __maybe_unused mmc_blk_fixups[] = { MMC_QUIRK_TRIM_BROKEN), /*

• * Micron MTFC4GACAJCN-1M advertises TRIM but it does not seems to
  

• * support being used to offload WRITE_ZEROES.
  

• * Micron MTFC4GACAJCN-1M supports TRIM but does not appear to suppor
  

• * WRITE_ZEROES offloading. It also supports caching, but the cache can
  

• * only be flushed after a write has occurred.
  

  */ MMC_FIXUP("Q2J54A", CID_MANFID_MICRON, 0x014e, add_quirk_mmc,

•   MMC_QUIRK_TRIM_BROKEN),
  

•   MMC_QUIRK_TRIM_BROKEN | MMC_QUIRK_BROKEN_CACHE_FLUSH),
  

/* * Kingston EMMC04G-M627 advertises TRIM but it does not seems to diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h index daa2f40d9ce6..7b12eebc5586 100644 --- a/include/linux/mmc/card.h +++ b/include/linux/mmc/card.h @@ -295,7 +295,9 @@ struct mmc_card { #define MMC_QUIRK_BROKEN_HPI (1<<13) /* Disable broken HPI support */ #define MMC_QUIRK_BROKEN_SD_DISCARD (1<<14) /* Disable broken SD discard support */ #define MMC_QUIRK_BROKEN_SD_CACHE (1<<15) /* Disable broken SD cache support */ +#define MMC_QUIRK_BROKEN_CACHE_FLUSH (1<<16) /* Don't flush cache until the write has occurred */

• bool written_flag; /* Indicates eMMC has been written since power on */ bool reenable_cmdq; /* Re-enable Command Queue */

unsigned int erase_size; /* erase size in sectors */