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: v4--v5: 1. In the case of a successful flush, set writing_flag in _mmc_flush_cache() 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 | 4 +++- drivers/mmc/core/card.h | 4 ++++ drivers/mmc/core/mmc.c | 8 ++++++-- drivers/mmc/core/quirks.h | 7 ++++--- include/linux/mmc/card.h | 2 ++ 5 files changed, 19 insertions(+), 6 deletions(-)
diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c index 3a8f27c3e310..152dfe593c43 100644 --- a/drivers/mmc/core/block.c +++ b/drivers/mmc/core/block.c @@ -2381,8 +2381,10 @@ 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: + 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 8180983bd402..11053f920ac4 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -2086,13 +2086,17 @@ 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, CACHE_FLUSH_TIMEOUT_MS); if (err) - pr_err("%s: cache flush error %d\n", - mmc_hostname(host), err); + pr_err("%s: cache flush error %d\n", mmc_hostname(host), err); + else + host->card->written_flag = false; }
return err; 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 */