[U-Boot] [PATCH] mmc: fix eMMC v5.1 incorrect version detection

[Alexander Kochetkov]

eMMC cards v5.1 has value 8 inside EXT_CSD_REV register.
The patch make EXT_CSD_REV value 8 match v5.1

The is a hole inside version enumeration. EXT_CSD_REV value 4
doens't correspond to any valid eMMC version. So EXT_CSD_REV
value 4 assigned undefined version.

Also the patch fix mmc_versions array bounds check. Value 8
produced out of array access.

Signed-off-by: Alexander Kochetkov <al.kochet at gmail.com>
---
 drivers/mmc/mmc.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 255310a..c8c13bd 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -1950,6 +1950,7 @@ static int mmc_startup_v4(struct mmc *mmc)
 		MMC_VERSION_4_1,
 		MMC_VERSION_4_2,
 		MMC_VERSION_4_3,
+		MMC_VERSION_UNKNOWN,
 		MMC_VERSION_4_41,
 		MMC_VERSION_4_5,
 		MMC_VERSION_5_0,
@@ -1973,7 +1974,8 @@ static int mmc_startup_v4(struct mmc *mmc)
 		return -ENOMEM;
 	memcpy(mmc->ext_csd, ext_csd, MMC_MAX_BLOCK_LEN);
 
-	if (ext_csd[EXT_CSD_REV] > ARRAY_SIZE(mmc_versions))
+	if (ext_csd[EXT_CSD_REV] >= ARRAY_SIZE(mmc_versions) ||
+	    ext_csd[EXT_CSD_REV] == 4)
 		return -EINVAL;
 
 	mmc->version = mmc_versions[ext_csd[EXT_CSD_REV]];
-- 
1.7.9.5