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>
This commit is contained in:
Shawn Guo 2011-11-10 16:39:32 +08:00 committed by Sascha Hauer
parent 1b929995eb
commit f750ba9b8d
2 changed files with 24 additions and 1 deletions

View File

@ -1139,7 +1139,7 @@ static int _clk_set_rate(struct clk *clk, unsigned long rate)
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 @@ int __init mx6q_clocks_init(void)
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);

View File

@ -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 @@ static int __devinit sdhci_esdhc_imx_probe(struct platform_device *pdev)
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) {