From: Stephen Warren swarren@nvidia.com
Some eMMC devices contain boot partitions, but do not set the PART_SUPPORT bit in EXT_CSD_PARTITIONING_SUPPORT. Allow partition selection on such devices, by enabling partition switching when EXT_CSD_BOOT_MULT is set.
Note that the Linux kernel enables access to boot partitions solely based on the value of EXT_CSD_BOOT_MULT; EXT_CSD_PARTITIONING_SUPPORT only influences access to "general" partitions.
eMMC devices affected by this issue exist on various NVIDIA Tegra platforms (and presumably many others too), such as Harmony (plug-in eMMC), Seaboard, Springbank, and Whistler (plug-in eMMC).
Signed-off-by: Stephen Warren swarren@nvidia.com --- drivers/mmc/mmc.c | 3 ++- include/mmc.h | 1 + 2 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index aebe578..3b08953 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -1157,7 +1157,8 @@ int mmc_startup(struct mmc *mmc) }
/* store the partition info of emmc */ - if (ext_csd[EXT_CSD_PARTITIONING_SUPPORT] & PART_SUPPORT) + if ((ext_csd[EXT_CSD_PARTITIONING_SUPPORT] & PART_SUPPORT) || + ext_csd[EXT_CSD_BOOT_MULT]) mmc->part_config = ext_csd[EXT_CSD_PART_CONF]; }
diff --git a/include/mmc.h b/include/mmc.h index 2305986..89df83c 100644 --- a/include/mmc.h +++ b/include/mmc.h @@ -159,6 +159,7 @@ #define EXT_CSD_CARD_TYPE 196 /* RO */ #define EXT_CSD_SEC_CNT 212 /* RO, 4 bytes */ #define EXT_CSD_HC_ERASE_GRP_SIZE 224 /* RO */ +#define EXT_CSD_BOOT_MULT 226 /* RO */
/* * EXT_CSD field definitions