If extended CSD was not available, the eMMC driver would incorrectly set the block size to 0, as the data_sector_size field of ext_csd was never initialized. This issue was exposed by commit 817046ecddbc ("block: Align max_hw_sectors to logical blocksize") which caused max_sectors and max_hw_sectors to be set to 0 after setting the block size to 0, resulting in a kernel panic in bio_split when attempting to read from the device. Fix it by only reading the block size from ext_csd if it is available. Fixes: 817046ecddbc ("block: Align max_hw_sectors to logical blocksize") Signed-off-by: Peter Collingbourne <pcc@xxxxxxxxxx> Link: https://linux-review.googlesource.com/id/If244d178da4d86b52034459438fec295b02d6e60 --- drivers/mmc/core/queue.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index de7cb0369c30..735cdbf1145c 100644 --- a/drivers/mmc/core/queue.c +++ b/drivers/mmc/core/queue.c @@ -20,6 +20,7 @@ #include "core.h" #include "card.h" #include "host.h" +#include "mmc_ops.h" #define MMC_DMA_MAP_MERGE_SEGMENTS 512 @@ -384,7 +385,7 @@ static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card) "merging was advertised but not possible"); blk_queue_max_segments(mq->queue, mmc_get_max_segments(host)); - if (mmc_card_mmc(card)) + if (mmc_card_mmc(card) && mmc_can_ext_csd(card)) block_size = card->ext_csd.data_sector_size; blk_queue_logical_block_size(mq->queue, block_size); -- 2.30.0.284.gd98b1dd5eaa7-goog