From: Adrian Hunter <adrian.hunter@intel.com>
To: Avri Altman <avri.altman@wdc.com>,
Ulf Hansson <ulf.hansson@linaro.org>,
linux-mmc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, Brendan Peter <bpeter@lytx.com>
Subject: Re: [PATCH 1/2] mmc: block: Issue flush only if allowed
Date: Mon, 22 Mar 2021 20:00:02 +0200 [thread overview]
Message-ID: <546a878b-f19a-ab6d-369c-aebf2941f024@intel.com> (raw)
In-Reply-To: <20210322133645.4901-2-avri.altman@wdc.com>
On 22/03/21 3:36 pm, Avri Altman wrote:
> The cache may be flushed to the nonvolatile storage by writing to
> FLUSH_CACHE byte (EXT_CSD byte [32]). When in command queueing mode, the
> cache may be flushed by issuing a CMDQ_TASK_ DEV_MGMT (CMD48) with a
> FLUSH_CACHE op-code. Either way, verify that The cache function is
> turned ON before doing so.
>
> fixes: 1e8e55b67030 (mmc: block: Add CQE support)
>
> Reported-by: Brendan Peter <bpeter@lytx.com>
> Tested-by: Brendan Peter <bpeter@lytx.com>
> Signed-off-by: Avri Altman <avri.altman@wdc.com>
> ---
> drivers/mmc/core/block.c | 3 +++
> drivers/mmc/core/mmc_ops.c | 4 +---
> drivers/mmc/core/mmc_ops.h | 5 +++++
> 3 files changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
> index 42e27a298218..a93c66aa91db 100644
> --- a/drivers/mmc/core/block.c
> +++ b/drivers/mmc/core/block.c
> @@ -1473,6 +1473,9 @@ static int mmc_blk_cqe_issue_flush(struct mmc_queue *mq, struct request *req)
> struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
> struct mmc_request *mrq = mmc_blk_cqe_prep_dcmd(mqrq, req);
>
> + if (mmc_card_mmc(mq->card) && !mmc_flush_allowed(mq->card))
> + return 0;
Returning 0 means the flush was issued successfully. i.e. it is in
flight.
Instead, a call to blk_mq_end_request(req, BLK_STS_OK) is needed,
and mmc_blk_mq_issue_rq() must be amended so that it will return
MMC_REQ_DONE for this case.
> +
> mrq->cmd->opcode = MMC_SWITCH;
> mrq->cmd->arg = (MMC_SWITCH_MODE_WRITE_BYTE << 24) |
> (EXT_CSD_FLUSH_CACHE << 16) |
> diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
> index baa6314f69b4..b8a0c9ac8a20 100644
> --- 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 *card)
> {
> int err = 0;
>
> - if (mmc_card_mmc(card) &&
> - (card->ext_csd.cache_size > 0) &&
> - (card->ext_csd.cache_ctrl & 1)) {
> + if (mmc_card_mmc(card) && mmc_flush_allowed(card)) {
> err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> EXT_CSD_FLUSH_CACHE, 1,
> MMC_CACHE_FLUSH_TIMEOUT_MS);
> diff --git a/drivers/mmc/core/mmc_ops.h b/drivers/mmc/core/mmc_ops.h
> index 632009260e51..bf2b315addd7 100644
> --- a/drivers/mmc/core/mmc_ops.h
> +++ b/drivers/mmc/core/mmc_ops.h
> @@ -19,6 +19,11 @@ enum mmc_busy_cmd {
> struct mmc_host;
> struct mmc_card;
>
> +static inline bool mmc_flush_allowed(struct mmc_card *card)
> +{
> + return card->ext_csd.cache_size > 0 && (card->ext_csd.cache_ctrl & 1);
> +}
> +
> int mmc_select_card(struct mmc_card *card);
> int mmc_deselect_cards(struct mmc_host *host);
> int mmc_set_dsr(struct mmc_host *host);
>
next prev parent reply other threads:[~2021-03-22 18:00 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-22 13:36 [PATCH 0/2] Do not flush cache when it is disabled Avri Altman
2021-03-22 13:36 ` [PATCH 1/2] mmc: block: Issue flush only if allowed Avri Altman
2021-03-22 18:00 ` Adrian Hunter [this message]
2021-03-22 13:36 ` [PATCH 2/2] mmc: block: Update ext_csd.cache_ctrl if it was written Avri Altman
2021-03-22 18:59 ` Adrian Hunter
2021-04-02 7:46 [PATCH 1/2] mmc: block: Issue flush only if allowed Avri Altman
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=546a878b-f19a-ab6d-369c-aebf2941f024@intel.com \
--to=adrian.hunter@intel.com \
--cc=avri.altman@wdc.com \
--cc=bpeter@lytx.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mmc@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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).