All of lore.kernel.org
 help / color / mirror / Atom feed
From: Bean Huo <beanhuo@iokpp.de>
To: ulf.hansson@linaro.org, cLoehle@hyperstone.com, adrian.hunter@intel.com
Cc: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
	Bean Huo <beanhuo@micron.com>,
	Rafael Beims <rafael.beims@toradex.com>,
	stable@vger.kernel.org
Subject: [v5] mmc: Add quirk MMC_QUIRK_BROKEN_CACHE_FLUSH for Micron eMMC Q2J54A
Date: Mon, 30 Oct 2023 23:48:09 +0100	[thread overview]
Message-ID: <20231030224809.59245-1-beanhuo@iokpp.de> (raw)

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 */
-- 
2.34.1


             reply	other threads:[~2023-10-30 22:48 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-30 22:48 Bean Huo [this message]
2023-11-03 11:16 ` [v5] mmc: Add quirk MMC_QUIRK_BROKEN_CACHE_FLUSH for Micron eMMC Q2J54A Ulf Hansson

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20231030224809.59245-1-beanhuo@iokpp.de \
    --to=beanhuo@iokpp.de \
    --cc=adrian.hunter@intel.com \
    --cc=beanhuo@micron.com \
    --cc=cLoehle@hyperstone.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mmc@vger.kernel.org \
    --cc=rafael.beims@toradex.com \
    --cc=stable@vger.kernel.org \
    --cc=ulf.hansson@linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.