From: Yangbo Lu <yangbo.lu@nxp.com>
Date: Fri, 17 Jan 2020 14:38:58 +0800
Subject: mmc: sdhci-of-esdhc: fix transfer mode register reading
Git-commit: 429d939c194b2e81e4a669671efc8c0c2fb9887e
Patch-mainline: v5.6-rc1
References: jsc#SLE-12251
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@nxp.com>
Link: https://lore.kernel.org/r/20200117063858.37296-1-yangbo.lu@nxp.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
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 8c06017bbe08..3ef4973c4da9 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
--
2.26.2