From 41591b38f5f8f78344954b68582b5f00e56ffe61 Mon Sep 17 00:00:00 2001 From: Chris Boot Date: Mon, 8 Oct 2018 17:07:30 +0200 Subject: [PATCH] mmc: block: avoid multiblock reads for the last sector in SPI mode MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Clément Péron Cc: stable@vger.kernel.org # v4.10+ Signed-off-by: Ulf Hansson --- drivers/mmc/core/block.c | 10 ++++++++++ 1 file changed, 10 insertions(+) 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 @@ -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 -- 2.30.2