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>
This commit is contained in:
Chris Boot 2018-10-08 17:07:30 +02:00 committed by Ulf Hansson
parent 0238df646e
commit 41591b38f5
1 changed files with 10 additions and 0 deletions

View File

@ -1370,6 +1370,16 @@ static void mmc_blk_data_prep(struct mmc_queue *mq, struct mmc_queue_req *mqrq,
brq->data.blocks = card->host->max_blk_count;
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