[PATCH 5.15 096/128] mmc: mmci: stm32: clear DLYB_CR after sending tuning command

Greg Kroah-Hartman
2021-12-27T15:47:39Z

From: Yann Gautier <yann.gautier@foss.st.com>

commit ff31ee0a0f471776f67be5e5275c18d17736fc6b upstream.

During test campaign, and especially after several unbind/bind sequences,
it has been seen that the SD-card on SDMMC1 thread could freeze.
The freeze always appear on a CMD23 following a CMD19.
Checking SDMMC internal registers shows that the tuning command (CMD19)
has failed.
The freeze is then due to the delay block involved in the tuning sequence.
To correct this, clear the delay block register DLYB_CR register after
the tuning commands.

Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Fixes: 1103f807a3b9 ("mmc: mmci_sdmmc: Add execute tuning with delay block")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211215141727.4901-4-yann.gautier@foss.st.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/mmc/host/mmci_stm32_sdmmc.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/mmc/host/mmci_stm32_sdmmc.c
+++ b/drivers/mmc/host/mmci_stm32_sdmmc.c
@@ -441,6 +441,8 @@ static int sdmmc_dlyb_phase_tuning(struc
return -EINVAL;
}

+ writel_relaxed(0, dlyb->base + DLYB_CR);
+
phase = end_of_len - max_len / 2;
sdmmc_dlyb_set_cfgr(dlyb, dlyb->unit, phase, false);