From 41591b38f5f8f78344954b68582b5f00e56ffe61 Mon Sep 17 00:00:00 2001
From: Chris Boot <bootc@bootc.net>
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=UTF-8
Content-transfer-encoding: 8bit
Git-commit: 41591b38f5f8f78344954b68582b5f00e56ffe61
Patch-mainline: v4.19-rc8
References: bsc#1051510
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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
--
2.19.0