[U-Boot] [PATCH 1/3] mmc: detect boot sectors using EXT_CSD_BOOT_MULT too

Stephen Warren swarren at wwwdotorg.org
Mon Jul 30 22:55:43 CEST 2012


From: Stephen Warren <swarren at 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 at 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
-- 
1.7.0.4



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