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authorGirish K S <girish.shivananjappa@linaro.org>2011-08-26 11:28:18 +0200
committerChris Ball <cjb@laptop.org>2011-08-31 22:25:52 +0200
commit49bb1e619568ec84785ceb366f07db2a6f0b64cc (patch)
tree4b08dd7298248cec43d56b8cd73e535f5f4130fd /drivers/mmc
parentmmc: sd: UHS-I bus speed should be set last in UHS initialization (diff)
downloadlinux-49bb1e619568ec84785ceb366f07db2a6f0b64cc.tar.xz
linux-49bb1e619568ec84785ceb366f07db2a6f0b64cc.zip
mmc: sdhci-s3c: Fix mmc card I/O problem
This patch fixes the problem in sdhci-s3c host driver for Samsung Soc's. During the card identification stage the mmc core driver enumerates for the best bus width in combination with the highest available data rate. It starts enumerating from the highest bus width (8) to lowest width (1). In case of few MMC cards the 4-bit bus enumeration fails and tries the 1-bit bus enumeration. When switched to 1-bit bus mode the host driver has to clear the previous bus width setting and apply the new setting. The current patch will clear the previous bus mode and apply the new mode setting. Signed-off-by: Girish K S <girish.shivananjappa@linaro.org> Acked-by: Jaehoon Chung <jh80.chung@samsung.com> Cc: <stable@kernel.org> Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/sdhci-s3c.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
index 2bd7bf4fece7..fe886d6c474a 100644
--- a/drivers/mmc/host/sdhci-s3c.c
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -302,6 +302,8 @@ static int sdhci_s3c_platform_8bit_width(struct sdhci_host *host, int width)
ctrl &= ~SDHCI_CTRL_8BITBUS;
break;
default:
+ ctrl &= ~SDHCI_CTRL_4BITBUS;
+ ctrl &= ~SDHCI_CTRL_8BITBUS;
break;
}