This is a note to let you know that I've just added the patch titled
mmc: Add quirk MMC_QUIRK_BROKEN_CACHE_FLUSH for Micron eMMC Q2J54A
to the 6.1-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-add-quirk-mmc_quirk_broken_cache_flush-for-micron-emmc-q2j54a.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ed9009ad300c0f15a3ecfe9613547b1962bde02c Mon Sep 17 00:00:00 2001
From: Bean Huo <beanhuo@xxxxxxxxxx>
Date: Mon, 30 Oct 2023 23:48:09 +0100
Subject: mmc: Add quirk MMC_QUIRK_BROKEN_CACHE_FLUSH for Micron eMMC Q2J54A
From: Bean Huo <beanhuo@xxxxxxxxxx>
commit ed9009ad300c0f15a3ecfe9613547b1962bde02c upstream.
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@xxxxxxxxxx>
Signed-off-by: Rafael Beims <rafael.beims@xxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20231030224809.59245-1-beanhuo@xxxxxxxx
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/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(-)
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -2404,8 +2404,10 @@ enum mmc_issued mmc_blk_mq_issue_rq(stru
}
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
--- a/drivers/mmc/core/card.h
+++ b/drivers/mmc/core/card.h
@@ -280,4 +280,8 @@ static inline int mmc_card_broken_sd_cac
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
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -2081,13 +2081,17 @@ static int _mmc_flush_cache(struct mmc_h
{
int err = 0;
+ if (mmc_card_broken_cache_flush(host->card) && !host->card->written_flag)
+ return 0;
+
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;
--- a/drivers/mmc/core/quirks.h
+++ b/drivers/mmc/core/quirks.h
@@ -117,11 +117,12 @@ static const struct mmc_fixup __maybe_un
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 support
+ * 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),
/*
* Some SD cards reports discard support while they don't
--- 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 */
Patches currently in stable-queue which might be from beanhuo@xxxxxxxxxx are
queue-6.1/mmc-add-quirk-mmc_quirk_broken_cache_flush-for-micron-emmc-q2j54a.patch
