From: Bean Huo <[email protected]>
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 <[email protected]>
Co-developed-by: Rafael Beims <[email protected]>
Cc: [email protected]
---
Changelog:
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/mmc.c | 5 +++++
drivers/mmc/core/quirks.h | 7 ++++---
include/linux/mmc/card.h | 2 ++
4 files changed, 15 insertions(+), 3 deletions(-)
diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 3a8f27c3e310..14d0dc7942de 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -2387,6 +2387,10 @@ enum mmc_issued mmc_blk_mq_issue_rq(struct mmc_queue *mq, struct request *req)
ret = mmc_blk_cqe_issue_rw_rq(mq, req);
else
ret = mmc_blk_mq_issue_rw_rq(mq, req);
+
+ if (host->card->quirks & MMC_QUIRK_BROKEN_CACHE_FLUSH &&
+ !host->card->written_flag && !ret)
+ host->card->written_flag = true;
break;
default:
WARN_ON_ONCE(1);
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 89cd48fcec79..a2edd065fa1b 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 (host->card->quirks & MMC_QUIRK_BROKEN_CACHE_FLUSH && !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 */
--
2.34.1
On Thu, Sep 21, 2023 at 10:34:26PM +0200, Bean Huo wrote:
> From: Bean Huo <[email protected]>
>
> 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 <[email protected]>
> Co-developed-by: Rafael Beims <[email protected]>
Then Rafael also has to sign off on this, right?
On Thu, Sep 21, 2023 at 10:34:26PM +0200, Bean Huo wrote:
> From: Bean Huo <[email protected]>
>
> 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 <[email protected]>
> Co-developed-by: Rafael Beims <[email protected]>
> Cc: [email protected]
> ---
> Changelog:
>
> 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/mmc.c | 5 +++++
> drivers/mmc/core/quirks.h | 7 ++++---
> include/linux/mmc/card.h | 2 ++
> 4 files changed, 15 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
> index 3a8f27c3e310..14d0dc7942de 100644
> --- a/drivers/mmc/core/block.c
> +++ b/drivers/mmc/core/block.c
> @@ -2387,6 +2387,10 @@ enum mmc_issued mmc_blk_mq_issue_rq(struct mmc_queue *mq, struct request *req)
> ret = mmc_blk_cqe_issue_rw_rq(mq, req);
> else
> ret = mmc_blk_mq_issue_rw_rq(mq, req);
> +
> + if (host->card->quirks & MMC_QUIRK_BROKEN_CACHE_FLUSH &&
> + !host->card->written_flag && !ret)
> + host->card->written_flag = true;
From what I can see this branch is followed for both REQ_OP_READ and
REQ_OP_WRITE, and I would say we want to set this flag only for
REQ_OP_WRITE.
Am I wrong?
Francesco
On 22/09/2023 06:29, Greg KH wrote:
> On Thu, Sep 21, 2023 at 10:34:26PM +0200, Bean Huo wrote:
>> From: Bean Huo <[email protected]>
>>
>> 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 <[email protected]>
>> Co-developed-by: Rafael Beims <[email protected]>
> Then Rafael also has to sign off on this, right?
>
Correct,
Signed-off-by: Rafael Beims <[email protected]>
Thanks,
Rafael
On Thu, 21 Sept 2023 at 22:35, Bean Huo <[email protected]> wrote:
>
> From: Bean Huo <[email protected]>
>
> 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 <[email protected]>
> Co-developed-by: Rafael Beims <[email protected]>
> Cc: [email protected]
> ---
> Changelog:
>
> 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/mmc.c | 5 +++++
> drivers/mmc/core/quirks.h | 7 ++++---
> include/linux/mmc/card.h | 2 ++
> 4 files changed, 15 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
> index 3a8f27c3e310..14d0dc7942de 100644
> --- a/drivers/mmc/core/block.c
> +++ b/drivers/mmc/core/block.c
> @@ -2387,6 +2387,10 @@ enum mmc_issued mmc_blk_mq_issue_rq(struct mmc_queue *mq, struct request *req)
> ret = mmc_blk_cqe_issue_rw_rq(mq, req);
> else
> ret = mmc_blk_mq_issue_rw_rq(mq, req);
> +
> + if (host->card->quirks & MMC_QUIRK_BROKEN_CACHE_FLUSH &&
Please add an inline helper function for this in
drivers/mmc/core/card.h, along with the others.
[...]
Kind regards
Uffe
On Fri, 2023-09-22 at 19:01 +0200, Francesco Dolcini wrote:
> > +
> > + if (host->card->quirks &
> > MMC_QUIRK_BROKEN_CACHE_FLUSH &&
> > + !host->card->written_flag && !ret)
> > + host->card->written_flag = true;
>
> From what I can see this branch is followed for both REQ_OP_READ and
> REQ_OP_WRITE, and I would say we want to set this flag only for
> REQ_OP_WRITE.
>
> Am I wrong?
>
> Francesco
you are right, we only care about write, I will update it in the next
version, thanks for your review!
Kind regards,
Bean