Andy-ld Lu 6888e6835b mmc: mtk-sd: Fix register settings for hs400(es) mode
commit 3e68abf2b9cebe76c6cd4b1aca8e95cd671035a3 upstream.

For hs400(es) mode, the 'hs400-ds-delay' is typically configured in the
dts. However, some projects may only define 'mediatek,hs400-ds-dly3',
which can lead to initialization failures in hs400es mode. CMD13 reported
response crc error in the mmc_switch_status() just after switching to
hs400es mode.

[    1.914038][   T82] mmc0: mmc_select_hs400es failed, error -84
[    1.914954][   T82] mmc0: error -84 whilst initialising MMC card

Currently, the hs400_ds_dly3 value is set within the tuning function. This
means that the PAD_DS_DLY3 field is not configured before tuning process,
which is the reason for the above-mentioned CMD13 response crc error.

Move the PAD_DS_DLY3 field configuration into msdc_prepare_hs400_tuning(),
and add a value check of hs400_ds_delay to prevent overwriting by zero when
the 'hs400-ds-delay' is not set in the dts. In addition, since hs400(es)
only tune the PAD_DS_DLY1, the PAD_DS_DLY2_SEL bit should be cleared to
bypass it.

Fixes: c4ac38c653 ("mmc: mtk-sd: Add HS400 online tuning support")
Signed-off-by: Andy-ld Lu <andy-ld.lu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250123092644.7359-1-andy-ld.lu@mediatek.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-21 13:50:05 +01:00
2024-12-14 19:53:51 +01:00
2022-09-28 09:02:20 +02:00

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