]> git.ipfire.org Git - thirdparty/kernel/stable.git/commit
mmc: sdhci: Disable SD card clock before changing parameters
authorErick Shepherd <erick.shepherd@ni.com>
Tue, 11 Feb 2025 21:46:45 +0000 (15:46 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 4 Jun 2025 12:37:57 +0000 (14:37 +0200)
commit1acb22d09f5c46e16123394f3046407b403a1d69
tree28bce8cee6c3a24756078950bd99ddeb7b042270
parent8d52676f791d4baace2ce4f1166dcc7e6c3043d1
mmc: sdhci: Disable SD card clock before changing parameters

[ Upstream commit fb3bbc46c94f261b6156ee863c1b06c84cf157dc ]

Per the SD Host Controller Simplified Specification v4.20 ยง3.2.3, change
the SD card clock parameters only after first disabling the external card
clock. Doing this fixes a spurious clock pulse on Baytrail and Apollo Lake
SD controllers which otherwise breaks voltage switching with a specific
Swissbit SD card.

Signed-off-by: Kyle Roeschley <kyle.roeschley@ni.com>
Signed-off-by: Brad Mouring <brad.mouring@ni.com>
Signed-off-by: Erick Shepherd <erick.shepherd@ni.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20250211214645.469279-1-erick.shepherd@ni.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/mmc/host/sdhci.c