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

[Yann Gautier]

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 <yann.gaut...@foss.st.com>
---
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.gaut...@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)
+                       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;
 
        base_dlyb = devm_of_iomap(mmc_dev(host->mmc), np, 1, NULL);
        if (IS_ERR(base_dlyb))
-- 
2.17.1