linux/drivers/mmc
Luke Wang cb301583f4 mmc: sdhci: fix timing selection for 1-bit bus width
commit 5e3486e640 upstream.

When 1-bit bus width is used with HS200/HS400 capabilities set,
mmc_select_hs200() returns 0 without actually switching. This
causes mmc_select_timing() to skip mmc_select_hs(), leaving eMMC
in legacy mode (26MHz) instead of High Speed SDR (52MHz).

Per JEDEC eMMC spec section 5.3.2, 1-bit mode supports High Speed
SDR. Drop incompatible HS200/HS400/UHS/DDR caps early so timing
selection falls through to mmc_select_hs() correctly.

Fixes: f2119df6b7 ("mmc: sd: add support for signal voltage switch procedure")
Signed-off-by: Luke Wang <ziniu.wang_1@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2026-04-18 10:33:17 +02:00
..
core mmc: core: use sysfs_emit() instead of sprintf() 2026-01-19 13:10:11 +01:00
host mmc: sdhci: fix timing selection for 1-bit bus width 2026-04-18 10:33:17 +02:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00