From f750ba9b8db2a926c315ccfa9e95d12fe4590a22 Mon Sep 17 00:00:00 2001 From: Shawn Guo Date: Thu, 10 Nov 2011 16:39:32 +0800 Subject: [PATCH] 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 Cc: Chris Ball Cc: Sascha Hauer Signed-off-by: Sascha Hauer --- arch/arm/mach-imx/clock-imx6q.c | 17 ++++++++++++++++- drivers/mmc/host/sdhci-esdhc-imx.c | 8 ++++++++ 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-imx/clock-imx6q.c b/arch/arm/mach-imx/clock-imx6q.c index e0b926dfeced..613a1b993bff 100644 --- a/arch/arm/mach-imx/clock-imx6q.c +++ b/arch/arm/mach-imx/clock-imx6q.c @@ -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); diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index ae57769ba50d..4b976f00ea85 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 @@ 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) {