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Commit f23cc3ba authored by Raul E Rangel's avatar Raul E Rangel Committed by Ulf Hansson
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mmc: sdhci-acpi: AMDI0040: Set SDHCI_QUIRK2_PRESET_VALUE_BROKEN



This change fixes HS400 tuning for devices with invalid presets.

SDHCI presets are not currently used for eMMC HS/HS200/HS400, but are
used for DDR52. The HS400 retuning sequence is:

    HS400->DDR52->HS->HS200->Perform Tuning->HS->HS400

This means that when HS400 tuning happens, we transition through DDR52
for a very brief period. This causes presets to be enabled
unintentionally and stay enabled when transitioning back to HS200 or
HS400. Some firmware has invalid presets, so we end up with driver
strengths that can cause I/O problems.

Fixes: 34597a3f ("mmc: sdhci-acpi: Add support for ACPI HID of AMD Controller with HS400")
Signed-off-by: default avatarRaul E Rangel <rrangel@chromium.org>
Acked-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200928154718.1.Icc21d4b2f354e83e26e57e270dc952f5fe0b0a40@changeid


Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 764384d0
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