mmc: sdhci-of-esdhc: avoid writing power control register
The eSDHC doesn't have a standard power control register, so when
writing this register in stack we should do nothing to avoid
incorrect operation.
Signed-off-by: Yangbo Lu <yangbo.lu@freescale.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index 7b9282b..90e94a0 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -183,6 +183,12 @@
int shift = (spec_reg & 0x3) * 8;
/*
+ * eSDHC doesn't have a standard power control register, so we do
+ * nothing here to avoid incorrect operation.
+ */
+ if (spec_reg == SDHCI_POWER_CONTROL)
+ return old_value;
+ /*
* "DMA select" location is offset 0x28 in SD specification, but on
* P5020 or P3041, it's located at 0x29.
*/