Thread (3 messages) 3 messages, 2 authors, 2021-03-02

Re: [PATCH v2] mmc: mmci: manage MMC_CAP_NEED_RSP_BUSY for stm32 variant

From: Ulf Hansson <hidden>
Date: 2021-03-02 11:02:25
Also in: linux-mmc, lkml

On Thu, 25 Feb 2021 at 15:55, Yann Gautier [off-list ref] wrote:
quoted hunk ↗ jump to hunk
To properly manage commands awaiting R1B responses, the capability
MMC_CAP_NEED_RSP_BUSY is enabled in mmci driver, for stm32 variant.
The issue was seen on STM32MP157C-EV1 board, with an erase command,
with secure erase argument, letting the card stuck, possibly waiting
for 4 hours before timeout.

Fixes: 94fe2580a2f3 ("mmc: core: Enable erase/discard/trim support for all mmc hosts")

Signed-off-by: Yann Gautier <redacted>
---
This is somehow a v2 for patch [1].
Changes:
- Only apply MMC_CAP_NEED_RSP_BUSY to stm32 variant
- Cap the used timeout written to MMCIDATATIMER (when using
MMC_CAP_NEED_RSP_BUSY, cmd->busy_timeout may be greater than
host->max_busy_timeout)

 [1] https://patchwork.kernel.org/project/linux-mmc/patch/20210204120547.15381-2-yann.gautier@foss.st.com/

 drivers/mmc/host/mmci.c             | 8 +++++++-
 drivers/mmc/host/mmci_stm32_sdmmc.c | 1 +
 2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 17dbc81c221e..89e0e9ccfb71 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1242,7 +1242,13 @@ mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
                if (!cmd->busy_timeout)
                        cmd->busy_timeout = 10 * MSEC_PER_SEC;

-               clks = (unsigned long long)cmd->busy_timeout * host->cclk;
+               if (host->mmc->caps & MMC_CAP_NEED_RSP_BUSY &&
+                   host->mmc->max_busy_timeout &&
+                   cmd->busy_timeout > host->mmc->max_busy_timeout)
We are already within "if (host->variant->busy_timeout ....", a few
lines above, which means this can be simplified into:

if (cmd->busy_timeout > host->mmc->max_busy_timeout)
quoted hunk ↗ jump to hunk
+                       clks = (unsigned long long)host->mmc->max_busy_timeout * host->cclk;
+               else
+                       clks = (unsigned long long)cmd->busy_timeout * host->cclk;
+
                do_div(clks, MSEC_PER_SEC);
                writel_relaxed(clks, host->base + MMCIDATATIMER);
        }
diff --git a/drivers/mmc/host/mmci_stm32_sdmmc.c b/drivers/mmc/host/mmci_stm32_sdmmc.c
index 51db30acf4dc..2ad577618324 100644
--- a/drivers/mmc/host/mmci_stm32_sdmmc.c
+++ b/drivers/mmc/host/mmci_stm32_sdmmc.c
@@ -522,6 +522,7 @@ void sdmmc_variant_init(struct mmci_host *host)

        host->ops = &sdmmc_variant_ops;
        host->pwr_reg = readl_relaxed(host->base + MMCIPOWER);
+       host->mmc->caps |= MMC_CAP_NEED_RSP_BUSY;
To make it more clear that this is for variants having the
->busy_timeout flag set, I suggest to move this into mmci_probe().
        base_dlyb = devm_of_iomap(mmc_dev(host->mmc), np, 1, NULL);
        if (IS_ERR(base_dlyb))
--
2.17.1
Well, I decided to help out a bit. I have amend the patch according to
the above and extended the commit message with some valuable
information, based upon our earlier discussions.

Patch is applied at my fixes branch with a stable tag, please have a
look, test and shout at me if there is something that looks wrong!

Thanks and kind regards
Uffe

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