This is a note to let you know that I've just added the patch titled mmc: block: Issue a cache flush only when it's enabled to the 5.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mmc-block-issue-a-cache-flush-only-when-it-s-enabled.patch and it can be found in the queue-5.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 97fce126e279690105ee15be652b465fd96f9997 Mon Sep 17 00:00:00 2001 From: Avri Altman <avri.altman@xxxxxxx> Date: Sun, 25 Apr 2021 09:02:06 +0300 Subject: mmc: block: Issue a cache flush only when it's enabled From: Avri Altman <avri.altman@xxxxxxx> commit 97fce126e279690105ee15be652b465fd96f9997 upstream. In command queueing mode, the cache isn't flushed via the mmc_flush_cache() function, but instead by issuing a CMDQ_TASK_MGMT (CMD48) with a FLUSH_CACHE opcode. In this path, we need to check if cache has been enabled, before deciding to flush the cache, along the lines of what's being done in mmc_flush_cache(). To fix this problem, let's add a new bus ops callback ->cache_enabled() and implement it for the mmc bus type. In this way, the mmc block device driver can call it to know whether cache flushing should be done. Fixes: 1e8e55b67030 (mmc: block: Add CQE support) Cc: stable@xxxxxxxxxxxxxxx Reported-by: Brendan Peter <bpeter@xxxxxxxx> Signed-off-by: Avri Altman <avri.altman@xxxxxxx> Tested-by: Brendan Peter <bpeter@xxxxxxxx> Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx> Link: https://lore.kernel.org/r/20210425060207.2591-2-avri.altman@xxxxxxx Link: https://lore.kernel.org/r/20210425060207.2591-3-avri.altman@xxxxxxx [Ulf: Squashed the two patches and made some minor updates] Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/mmc/core/block.c | 4 ++++ drivers/mmc/core/core.h | 9 +++++++++ drivers/mmc/core/mmc.c | 7 +++++++ drivers/mmc/core/mmc_ops.c | 4 +--- 4 files changed, 21 insertions(+), 3 deletions(-) --- a/drivers/mmc/core/block.c +++ b/drivers/mmc/core/block.c @@ -2236,6 +2236,10 @@ enum mmc_issued mmc_blk_mq_issue_rq(stru case MMC_ISSUE_ASYNC: switch (req_op(req)) { case REQ_OP_FLUSH: + if (!mmc_cache_enabled(host)) { + blk_mq_end_request(req, BLK_STS_OK); + return MMC_REQ_FINISHED; + } ret = mmc_blk_cqe_issue_flush(mq, req); break; case REQ_OP_READ: --- a/drivers/mmc/core/core.h +++ b/drivers/mmc/core/core.h @@ -29,6 +29,7 @@ struct mmc_bus_ops { int (*shutdown)(struct mmc_host *); int (*hw_reset)(struct mmc_host *); int (*sw_reset)(struct mmc_host *); + bool (*cache_enabled)(struct mmc_host *); }; void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops); @@ -171,4 +172,12 @@ static inline void mmc_post_req(struct m host->ops->post_req(host, mrq, err); } +static inline bool mmc_cache_enabled(struct mmc_host *host) +{ + if (host->bus_ops->cache_enabled) + return host->bus_ops->cache_enabled(host); + + return false; +} + #endif --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -2029,6 +2029,12 @@ static void mmc_detect(struct mmc_host * } } +static bool _mmc_cache_enabled(struct mmc_host *host) +{ + return host->card->ext_csd.cache_size > 0 && + host->card->ext_csd.cache_ctrl & 1; +} + static int _mmc_suspend(struct mmc_host *host, bool is_suspend) { int err = 0; @@ -2208,6 +2214,7 @@ static const struct mmc_bus_ops mmc_ops .alive = mmc_alive, .shutdown = mmc_shutdown, .hw_reset = _mmc_hw_reset, + .cache_enabled = _mmc_cache_enabled, }; /* --- a/drivers/mmc/core/mmc_ops.c +++ b/drivers/mmc/core/mmc_ops.c @@ -988,9 +988,7 @@ int mmc_flush_cache(struct mmc_card *car { int err = 0; - if (mmc_card_mmc(card) && - (card->ext_csd.cache_size > 0) && - (card->ext_csd.cache_ctrl & 1)) { + if (mmc_cache_enabled(card->host)) { err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_FLUSH_CACHE, 1, MMC_CACHE_FLUSH_TIMEOUT_MS); Patches currently in stable-queue which might be from avri.altman@xxxxxxx are queue-5.12/mmc-block-issue-a-cache-flush-only-when-it-s-enabled.patch queue-5.12/mmc-block-update-ext_csd.cache_ctrl-if-it-was-written.patch