From c08592698534f390afe726c38301aa8f1620c361 Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Tue, 22 Sep 2009 16:45:11 -0700 Subject: [PATCH] sdhci-of: avoid writing reserved bits into host control register SDHCI core tries to write HISPD bit into the host control register, but the eSDHC controllers don't have that bit, and that causes all sorts of misbehaviour when using 4-bit mode capable SD cards. Signed-off-by: Anton Vorontsov Cc: Pierre Ossman Cc: Kumar Gala Cc: David Vrabel Cc: Ben Dooks Cc: Sascha Hauer Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/mmc/host/sdhci-of.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/mmc/host/sdhci-of.c b/drivers/mmc/host/sdhci-of.c index 2b0756934f4..3439fc11890 100644 --- a/drivers/mmc/host/sdhci-of.c +++ b/drivers/mmc/host/sdhci-of.c @@ -48,6 +48,8 @@ struct sdhci_of_host { #define ESDHC_CLOCK_HCKEN 0x00000002 #define ESDHC_CLOCK_IPGEN 0x00000001 +#define ESDHC_HOST_CONTROL_RES 0x05 + static u32 esdhc_readl(struct sdhci_host *host, int reg) { return in_be32(host->ioaddr + reg); @@ -109,6 +111,10 @@ static void esdhc_writeb(struct sdhci_host *host, u8 val, int reg) int base = reg & ~0x3; int shift = (reg & 0x3) * 8; + /* Prevent SDHCI core from writing reserved bits (e.g. HISPD). */ + if (reg == SDHCI_HOST_CONTROL) + val &= ~ESDHC_HOST_CONTROL_RES; + clrsetbits_be32(host->ioaddr + base , 0xff << shift, val << shift); } -- 2.20.1