[ 3.5.y.z extended stable ] Patch "mmc: sdhci-esdhc-imx: fix host version read" has been added to staging queue

Luis Henriques luis.henriques at canonical.com
Thu Feb 28 11:58:53 UTC 2013

This is a note to let you know that I have just added a patch titled

    mmc: sdhci-esdhc-imx: fix host version read

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:


If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see



>From 145ea19fa2a3cb7f595b3927173238c043576759 Mon Sep 17 00:00:00 2001
From: Shawn Guo <shawn.guo at linaro.org>
Date: Tue, 15 Jan 2013 23:30:27 +0800
Subject: [PATCH] mmc: sdhci-esdhc-imx: fix host version read

commit ef4d0888bb7e1b963880f086575081c3d39cad2d upstream.

When commit 95a2482 (mmc: sdhci-esdhc-imx: add basic imx6q usdhc
support) works around host version issue on imx6q, it gets the
register address fixup "reg ^= 2" lost for imx25/35/51/53 esdhc.
Thus, the controller version on these SoCs is wrongly identified
as v1 while it's actually v2.

Add the address fixup back and take a different approach to correct
imx6q host version, so that the host version read gets back to work
for all SoCs.

Signed-off-by: Shawn Guo <shawn.guo at linaro.org>
Signed-off-by: Chris Ball <cjb at laptop.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
 drivers/mmc/host/sdhci-esdhc-imx.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index ebbe984..1dc06a6 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -237,15 +237,18 @@ static void esdhc_writel_le(struct sdhci_host *host, u32 val, int reg)

 static u16 esdhc_readw_le(struct sdhci_host *host, int reg)
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct pltfm_imx_data *imx_data = pltfm_host->priv;
 	if (unlikely(reg == SDHCI_HOST_VERSION)) {
-		u16 val = readw(host->ioaddr + (reg ^ 2));
-		/*
-		 * uSDHC supports SDHCI v3.0, but it's encoded as value
-		 * 0x3 in host controller version register, which violates
-		 * SDHCI_SPEC_300 definition.  Work it around here.
-		 */
-		if ((val & SDHCI_SPEC_VER_MASK) == 3)
-			return --val;
+		reg ^= 2;
+		if (is_imx6q_usdhc(imx_data)) {
+			/*
+			 * The usdhc register returns a wrong host version.
+			 * Correct it here.
+			 */
+			return SDHCI_SPEC_300;
+		}

 	return readw(host->ioaddr + reg);

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