mmc: detect boot sectors using EXT_CSD_BOOT_MULT too

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>
Signed-off-by: Tom Warren <twarren@nvidia.com>
This commit is contained in:
Stephen Warren 2012-07-30 10:55:43 +00:00 committed by Tom Warren
parent 0bc069b2e4
commit 29159057a1
2 changed files with 3 additions and 1 deletions

View File

@ -1162,7 +1162,8 @@ 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];
}

View File

@ -160,6 +160,7 @@
#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