Re: [PATCH v2 2/5] mmc: mmci: stm32: release the delay block before enabling it

From: Christophe KERELLO

Date: Thu Nov 05 2026 - 03:17:13 EST


Hello Mateusz,

On 11/4/26 16:27, Mateusz Nowicki wrote:
From: Christophe Kerello<christophe.kerello@xxxxxxxxxxx>

The delay block must be locked on the last frequency set. To avoid it
staying locked on a frequency used before, disable it first and wait for
the lock to drop before enabling it again.

Fixes: b5c3eb385797 ("mmc: mmci: stm32: add delay block support for STM32MP25")
Cc:stable@xxxxxxxxxxxxxxx
Signed-off-by: Christophe Kerello<christophe.kerello@xxxxxxxxxxx>
[Mateusz: reworded the commit message, added Fixes and Cc stable]
Signed-off-by: Mateusz Nowicki<mateusz.nowicki@xxxxxxxxxx>
---

Notes:
On the STM32MP257F-DK eMMC in HS200 at 150 MHz, switching from DDR52 to
HS200 made the tuning pick a wrong phase in 9 of 18 tries without this
change, the phase was right in all 12 tries with it.

drivers/mmc/host/mmci_stm32_sdmmc.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

Reviewed-by: Christophe Kerello <christophe.kerello@xxxxxxxxxxx>

Regards,
Christophe Kerello.