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>

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index c1c2862986432cd3a7be6d0600d6cb094ba0f004..551d6a9189eb474f0059cd411fede4834ef66026 100644 (file)
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -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];
        }
 

diff --git a/include/mmc.h b/include/mmc.h
index 7546b4a6c82393ab066696660593669fa3711f6a..b63b2c32a0960ca477ccb793ff1278aa1633147f 100644 (file)
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -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