[PATCH 3/4] mmc: sdhci-esdhc-imx: restore pinctrl before restoring ios timing on resume

[ziniu . wang_1]

From: Luke Wang <ziniu.wang_1@xxxxxxx>

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 default pinctrl state before
pm_runtime_force_resume(). The timing-specific pin configuration will
be set later by esdhc_change_pinstate() during runtime resume.

Fixes: 676a83855614 ("mmc: host: sdhci-esdhc-imx: refactor the system PM logic")
Signed-off-by: Luke Wang <ziniu.wang_1@xxxxxxx>
---
 drivers/mmc/host/sdhci-esdhc-imx.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index a944351dbcdf..a3688c94cf58 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -2114,6 +2114,10 @@ static int sdhci_esdhc_resume(struct device *dev)
 	struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host);
 	int ret;
 
+	ret = pinctrl_pm_select_default_state(dev);
+	if (ret)
+		return ret;
+
 	pm_runtime_force_resume(dev);
 
 	ret = mmc_gpio_set_cd_wake(host->mmc, false);
-- 
2.34.1