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/arch/arm/mach-imx/clock-imx6q.c b/arch/arm/mach-imx/clock-imx6q.c
index e0b926d..613a1b9 100644
--- a/arch/arm/mach-imx/clock-imx6q.c
+++ b/arch/arm/mach-imx/clock-imx6q.c
@@ -1139,7 +1139,7 @@
return -EINVAL;
max_div = ((d->bm_pred >> d->bp_pred) + 1) *
- ((d->bm_pred >> d->bp_pred) + 1);
+ ((d->bm_podf >> d->bp_podf) + 1);
div = parent_rate / rate;
if (div == 0)
@@ -2002,6 +2002,21 @@
clk_set_rate(&asrc_serial_clk, 1500000);
clk_set_rate(&enfc_clk, 11000000);
+ /*
+ * Before pinctrl API is available, we have to rely on the pad
+ * configuration set up by bootloader. For usdhc example here,
+ * u-boot sets up the pads for 49.5 MHz case, and we have to lower
+ * the usdhc clock from 198 to 49.5 MHz to match the pad configuration.
+ *
+ * FIXME: This is should be removed after pinctrl API is available.
+ * At that time, usdhc driver can call pinctrl API to change pad
+ * configuration dynamically per different usdhc clock settings.
+ */
+ clk_set_rate(&usdhc1_clk, 49500000);
+ clk_set_rate(&usdhc2_clk, 49500000);
+ clk_set_rate(&usdhc3_clk, 49500000);
+ clk_set_rate(&usdhc4_clk, 49500000);
+
np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-gpt");
base = of_iomap(np, 0);
WARN_ON(!base);