[PATCH v2] mmc: mtk-sd: Fix register settings for hs400(es) mode
From: Andy-ld Lu <hidden>
Date: 2025-01-23 09:26:55
Also in:
linux-mediatek, linux-mmc, lkml
Subsystem:
mediatek mmc/sd/sdio driver, multimedia card (mmc), secure digital (sd) and sdio subsystem, the rest · Maintainers:
Chaotian Jing, Ulf Hansson, Linus Torvalds
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: c4ac38c6539b ("mmc: mtk-sd: Add HS400 online tuning support")
Signed-off-by: Andy-ld Lu <redacted>
---
Changes in v2:
- Change commit title from 'optimize' to 'Fix'
- Add a Fixes tag
- Change spaces back to tabs
---
drivers/mmc/host/mtk-sd.c | 31 ++++++++++++++++++++-----------
1 file changed, 20 insertions(+), 11 deletions(-)
diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 4b6e91372526..345ea91629e0 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c@@ -273,6 +273,7 @@ #define MSDC_PAD_TUNE_CMD2_SEL BIT(21) /* RW */ #define PAD_DS_TUNE_DLY_SEL BIT(0) /* RW */ +#define PAD_DS_TUNE_DLY2_SEL BIT(1) /* RW */ #define PAD_DS_TUNE_DLY1 GENMASK(6, 2) /* RW */ #define PAD_DS_TUNE_DLY2 GENMASK(11, 7) /* RW */ #define PAD_DS_TUNE_DLY3 GENMASK(16, 12) /* RW */
@@ -318,6 +319,7 @@ /* EMMC50_PAD_DS_TUNE mask */ #define PAD_DS_DLY_SEL BIT(16) /* RW */ +#define PAD_DS_DLY2_SEL BIT(15) /* RW */ #define PAD_DS_DLY1 GENMASK(14, 10) /* RW */ #define PAD_DS_DLY3 GENMASK(4, 0) /* RW */
@@ -2504,13 +2506,23 @@ static int msdc_execute_tuning(struct mmc_host *mmc, u32 opcode) static int msdc_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_ios *ios) { struct msdc_host *host = mmc_priv(mmc); + host->hs400_mode = true; - if (host->top_base) - writel(host->hs400_ds_delay, - host->top_base + EMMC50_PAD_DS_TUNE); - else - writel(host->hs400_ds_delay, host->base + PAD_DS_TUNE); + if (host->top_base) { + if (host->hs400_ds_dly3) + sdr_set_field(host->top_base + EMMC50_PAD_DS_TUNE, + PAD_DS_DLY3, host->hs400_ds_dly3); + if (host->hs400_ds_delay) + writel(host->hs400_ds_delay, + host->top_base + EMMC50_PAD_DS_TUNE); + } else { + if (host->hs400_ds_dly3) + sdr_set_field(host->base + PAD_DS_TUNE, + PAD_DS_TUNE_DLY3, host->hs400_ds_dly3); + if (host->hs400_ds_delay) + writel(host->hs400_ds_delay, host->base + PAD_DS_TUNE); + } /* hs400 mode must set it to 0 */ sdr_clr_bits(host->base + MSDC_PATCH_BIT2, MSDC_PATCH_BIT2_CFGCRCSTS); /* to improve read performance, set outstanding to 2 */
@@ -2530,14 +2542,11 @@ static int msdc_execute_hs400_tuning(struct mmc_host *mmc, struct mmc_card *card if (host->top_base) { sdr_set_bits(host->top_base + EMMC50_PAD_DS_TUNE, PAD_DS_DLY_SEL); - if (host->hs400_ds_dly3) - sdr_set_field(host->top_base + EMMC50_PAD_DS_TUNE, - PAD_DS_DLY3, host->hs400_ds_dly3); + sdr_clr_bits(host->top_base + EMMC50_PAD_DS_TUNE, + PAD_DS_DLY2_SEL); } else { sdr_set_bits(host->base + PAD_DS_TUNE, PAD_DS_TUNE_DLY_SEL); - if (host->hs400_ds_dly3) - sdr_set_field(host->base + PAD_DS_TUNE, - PAD_DS_TUNE_DLY3, host->hs400_ds_dly3); + sdr_clr_bits(host->base + PAD_DS_TUNE, PAD_DS_TUNE_DLY2_SEL); } host->hs400_tuning = true;
--
2.46.0