[PATCH v2 3/5] mmc: sdhci-esdhc-imx: restore pinctrl before restoring ios timing on resume

[ziniu.wang_1 at oss.nxp.com]

From: Luke Wang <ziniu.wang_1 at nxp.com>

SDIO devices such as WiFi may keep power during suspend, so the MMC
core skips full card re-initialization on resume and directly restores
the host controller's ios timing to match the card. For DDR mode,
pm_runtime_force_resume() sets DDR_EN before the pin configuration is
restored from sleep state. When DDR_EN is set while the pinctrl is still
muxed to GPIO or other non-uSDHC function, the loopback clock from the
external pad is not valid, resulting in an incorrect internal sampling
point being selected. This causes persistent read CRC errors on subsequent
data transfers, even after the pinctrl is later configured correctly.

SD/eMMC running in DDR mode are unaffected as they are fully re-initialized
from legacy timing after resume.

Fix this by restoring the pinctrl state based on current timing mode
using esdhc_change_pinstate() before pm_runtime_force_resume(). This
ensures the correct pin configuration (e.g., 100/200MHz for UHS modes)
is applied. Only restore for non-wakeup devices since wakeup devices
kept their active pin state during suspend to avoid glitching the SD
bus pins for powered SDIO cards.

Fixes: 676a83855614 ("mmc: host: sdhci-esdhc-imx: refactor the system PM logic")
Signed-off-by: Luke Wang <ziniu.wang_1 at nxp.com>
---
 drivers/mmc/host/sdhci-esdhc-imx.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index a944351dbcdf..7fcaecdd4ec6 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -2114,6 +2114,12 @@ static int sdhci_esdhc_resume(struct device *dev)
 	struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host);
 	int ret;
 
+	if (!device_may_wakeup(dev)) {
+		ret = esdhc_change_pinstate(host, host->timing);
+		if (ret)
+			dev_warn(dev, "Failed to restore pinctrl state\n");
+	}
+
 	pm_runtime_force_resume(dev);
 
 	ret = mmc_gpio_set_cd_wake(host->mmc, false);
-- 
2.34.1