From: Mateusz Nowak <mateusz.nowak@xxxxxxxxx> Fixes: ca369d51b3e1 ("block/sd: Fix device-imposed transfer length limits") introduced max_dev_sectors as upper limit for max_hw_sectors. This caused limitation of maximum block size to default max_dev_sectors value - 127, causing performance degradation with higher block sizes. This patch is overriding max_dev_sectors value, so it will be set to maximum possible value to be used with set block count command, so 0xffff for eMMC cards, and 0xffffffff for SD cards. Fixes: ca369d51b3e1 ("block/sd: Fix device-imposed transfer length limits") Cc: linux-mmc@xxxxxxxxxxxxxxx Signed-off-by: Mateusz Nowak <mateusz.nowak@xxxxxxxxx> --- drivers/mmc/card/queue.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c index 6f4323c6d653..9175b8cd54de 100644 --- a/drivers/mmc/card/queue.c +++ b/drivers/mmc/card/queue.c @@ -212,6 +212,16 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, if (mmc_can_erase(card)) mmc_queue_setup_discard(mq->queue, card); + /* + * Set maximum block count accepted by the card. + * For eMMC, this can be 16 bit value, + * for SD, this can be 32 bit value + */ + if (mmc_card_mmc(card)) + blk_queue_max_dev_sectors(mq->queue, 0xffff); + else if (mmc_card_sd(card)) + blk_queue_max_dev_sectors(mq->queue, 0xffffffff); + #ifdef CONFIG_MMC_BLOCK_BOUNCE if (host->max_segs == 1) { unsigned int bouncesz; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html