From: ziniu.wang_1@nxp.com
To: adrian.hunter@intel.com, ulf.hansson@linaro.org, haibo.chen@nxp.com
Cc: Frank.Li@nxp.com, s.hauer@pengutronix.de, kernel@pengutronix.de,
festevam@gmail.com, imx@lists.linux.dev,
linux-mmc@vger.kernel.org, s32@nxp.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v3 1/4] mmc: sdhci: fix timing selection for 1-bit bus width
Date: Wed, 11 Mar 2026 17:50:06 +0800 [thread overview]
Message-ID: <20260311095009.1254556-2-ziniu.wang_1@nxp.com> (raw)
In-Reply-To: <20260311095009.1254556-1-ziniu.wang_1@nxp.com>
From: Luke Wang <ziniu.wang_1@nxp.com>
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: f2119df6b7646 ("mmc: sd: add support for signal voltage switch procedure")
Signed-off-by: Luke Wang <ziniu.wang_1@nxp.com>
---
drivers/mmc/host/sdhci.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index b1a3cd574c84..605be55f8d2d 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -4539,8 +4539,15 @@ int sdhci_setup_host(struct sdhci_host *host)
* their platform code before calling sdhci_add_host(), and we
* won't assume 8-bit width for hosts without that CAP.
*/
- if (!(host->quirks & SDHCI_QUIRK_FORCE_1_BIT_DATA))
+ if (host->quirks & SDHCI_QUIRK_FORCE_1_BIT_DATA) {
+ host->caps1 &= ~(SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 | SDHCI_SUPPORT_DDR50);
+ if (host->quirks2 & SDHCI_QUIRK2_CAPS_BIT63_FOR_HS400)
+ host->caps1 &= ~SDHCI_SUPPORT_HS400;
+ mmc->caps2 &= ~(MMC_CAP2_HS200 | MMC_CAP2_HS400 | MMC_CAP2_HS400_ES);
+ mmc->caps &= ~(MMC_CAP_DDR | MMC_CAP_UHS);
+ } else {
mmc->caps |= MMC_CAP_4_BIT_DATA;
+ }
if (host->quirks2 & SDHCI_QUIRK2_HOST_NO_CMD23)
mmc->caps &= ~MMC_CAP_CMD23;
--
2.34.1
next prev parent reply other threads:[~2026-03-11 9:48 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-11 9:50 [PATCH v3 0/4] mmc: sdhci-esdhc-imx: add 1-bit bus width support ziniu.wang_1
2026-03-11 9:50 ` ziniu.wang_1 [this message]
2026-03-11 9:58 ` [PATCH v3 1/4] mmc: sdhci: fix timing selection for 1-bit bus width Adrian Hunter
2026-03-16 15:15 ` Ulf Hansson
2026-03-11 9:50 ` [PATCH v3 2/4] mmc: sdhci-esdhc-imx: add 1-bit bus width support ziniu.wang_1
2026-03-11 10:03 ` Bough Chen
2026-03-16 15:15 ` Ulf Hansson
2026-03-11 9:50 ` [PATCH v3 3/4] mmc: sdhci-esdhc-imx: remove duplicate HS400 bus width validation ziniu.wang_1
2026-03-11 10:03 ` Bough Chen
2026-03-16 15:15 ` Ulf Hansson
2026-03-11 9:50 ` [PATCH v3 4/4] mmc: sdhci-pltfm: remove duplicate DTS property parsing ziniu.wang_1
2026-03-16 15:15 ` Ulf Hansson
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