The standard SD controller uses two 16-bit registers for command sending. 0xC: Transfer Mode Register 0xE: Command Register But the eSDHC controller uses one 32-bit register instead. 0xC: XFERTYPE For Transfer Mode Register and Command Register writing, the eSDHC driver will store Transfer Mode Register value in a variable first. When Command Register writing happens, driver will directly write a 32-bit value into XFERTYPE register. But for Transfer Mode Register reading, driver just returns a actual value. This may cause issue for some read-modify-write operations. We should make both reading and write on that variable for Transfer Mode Register. Signed-off-by: Yangbo Lu <yangbo.lu@xxxxxxx> --- drivers/mmc/host/sdhci-of-esdhc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c index 8c06017..3ef4973 100644 --- a/drivers/mmc/host/sdhci-of-esdhc.c +++ b/drivers/mmc/host/sdhci-of-esdhc.c @@ -173,6 +173,9 @@ static u16 esdhc_readw_fixup(struct sdhci_host *host, u16 ret; int shift = (spec_reg & 0x2) * 8; + if (spec_reg == SDHCI_TRANSFER_MODE) + return pltfm_host->xfer_mode_shadow; + if (spec_reg == SDHCI_HOST_VERSION) ret = value & 0xffff; else -- 2.7.4
