arm/imx: fix imx6q mmc error when mounting rootfs
The following error is seen in some case when mounting rootfs from
SD/MMC cards.
Waiting for root device /dev/mmcblk0p1...
mmc1: host does not support reading read-only switch. assuming write-enable.
mmc1: new high speed SDHC card at address b368
mmcblk0: mmc1:b368 SDC 3.74 GiB
mmcblk0: p1
mmc1: Timeout waiting for hardware interrupt.
mmcblk0: error -110 transferring data, sector 3678224, nr 40, cmd response 0x900, card status 0xc00
end_request: I/O error, dev mmcblk0, sector 3678225
Buffer I/O error on device mmcblk0p1, logical block 458754
lost page write due to I/O error on mmcblk0p1
This patch fixes the problem by lowering the usdhc clock and correcting
watermark configuration.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Chris Ball <cjb@laptop.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index ae57769..4b976f0 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -32,6 +32,7 @@
/* VENDOR SPEC register */
#define SDHCI_VENDOR_SPEC 0xC0
#define SDHCI_VENDOR_SPEC_SDIO_QUIRK 0x00000002
+#define SDHCI_WTMK_LVL 0x44
#define SDHCI_MIX_CTRL 0x48
/*
@@ -476,6 +477,13 @@
if (is_imx53_esdhc(imx_data))
imx_data->flags |= ESDHC_FLAG_MULTIBLK_NO_INT;
+ /*
+ * The imx6q ROM code will change the default watermark level setting
+ * to something insane. Change it back here.
+ */
+ if (is_imx6q_usdhc(imx_data))
+ writel(0x08100810, host->ioaddr + SDHCI_WTMK_LVL);
+
boarddata = &imx_data->boarddata;
if (sdhci_esdhc_imx_probe_dt(pdev, boarddata) < 0) {
if (!host->mmc->parent->platform_data) {