[U-Boot] [PATCH 2/3] mmc: invalidate block cache after hwpart switched successfully

[Weijie Gao]

eMMC device has multiple hw partitions both address from zero. However the
mmc driver lacks block cache invalidation for switch hwpart. This causes a
problem that data of current hw partition is cached before switching to
another hw partition. And the following read operation of the latter hw
partition will get wrong data when reading from the addresses that have
been cached previously.

To solve this problem, invalidate block cache after a successful
mmc_switch_part() operation.

Signed-off-by: Weijie Gao <weijie.gao at mediatek.com>
---
 drivers/mmc/mmc-uclass.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/mmc-uclass.c b/drivers/mmc/mmc-uclass.c
index 551007905c..2b146ea43c 100644
--- a/drivers/mmc/mmc-uclass.c
+++ b/drivers/mmc/mmc-uclass.c
@@ -360,6 +360,7 @@ static int mmc_select_hwpart(struct udevice *bdev, int hwpart)
 	struct udevice *mmc_dev = dev_get_parent(bdev);
 	struct mmc *mmc = mmc_get_mmc_dev(mmc_dev);
 	struct blk_desc *desc = dev_get_uclass_platdata(bdev);
+	int ret;
 
 	if (desc->hwpart == hwpart)
 		return 0;
@@ -367,7 +368,11 @@ static int mmc_select_hwpart(struct udevice *bdev, int hwpart)
 	if (mmc->part_config == MMCPART_NOAVAILABLE)
 		return -EMEDIUMTYPE;
 
-	return mmc_switch_part(mmc, hwpart);
+	ret = mmc_switch_part(mmc, hwpart);
+	if (!ret)
+		blkcache_invalidate(desc->if_type, desc->devnum);
+
+	return ret;
 }
 
 static int mmc_blk_probe(struct udevice *dev)
-- 
2.17.1