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authorChris Boot <bootc@bootc.net>2018-10-08 17:07:30 +0200
committerUlf Hansson <ulf.hansson@linaro.org>2018-10-09 09:23:00 +0200
commit41591b38f5f8f78344954b68582b5f00e56ffe61 (patch)
tree78a25d39a5515767dea363d066aafc0ee459f1f8 /drivers
parent0238df646e6224016a45505d2c111a24669ebe21 (diff)
mmc: block: avoid multiblock reads for the last sector in SPI mode
On some SD cards over SPI, reading with the multiblock read command the last sector will leave the card in a bad state. Remove last sectors from the multiblock reading cmd. Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Clément Péron <peron.clem@gmail.com> Cc: stable@vger.kernel.org # v4.10+ Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/mmc/core/block.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index a0b9102c4c6e..e201ccb3fda4 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -1371,6 +1371,16 @@ static void mmc_blk_data_prep(struct mmc_queue *mq, struct mmc_queue_req *mqrq,
if (brq->data.blocks > 1) {
/*
+ * Some SD cards in SPI mode return a CRC error or even lock up
+ * completely when trying to read the last block using a
+ * multiblock read command.
+ */
+ if (mmc_host_is_spi(card->host) && (rq_data_dir(req) == READ) &&
+ (blk_rq_pos(req) + blk_rq_sectors(req) ==
+ get_capacity(md->disk)))
+ brq->data.blocks--;
+
+ /*
* After a read error, we redo the request one sector
* at a time in order to accurately determine which
* sectors can be read successfully.