2 files changed, 17 insertions, 0 deletions

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index ede41f05c392..adab9038f6f7 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1402,6 +1402,16 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
                 if (card->host->caps2 & MMC_CAP2_NO_MULTI_READ &&
                     rq_data_dir(req) == READ)
                         brq->data.blocks = 1;
+
+                /*
+                 * Some controllers have HW issues while operating
+                 * in multiple I/O mode
+                 */
+                if (card->host->ops->multi_io_quirk)
+                        brq->data.blocks = card->host->ops->multi_io_quirk(card,
+                                                (rq_data_dir(req) == READ) ?
+                                                MMC_DATA_READ : MMC_DATA_WRITE,
+                                                brq->data.blocks);
         }
 
         if (brq->data.blocks > 1 || do_rel_wr) {
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 4cbf61476999..10e2bd6985ae 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -139,6 +139,13 @@ struct mmc_host_ops {
         int     (*select_drive_strength)(unsigned int max_dtr, int host_drv, int card_drv);
         void    (*hw_reset)(struct mmc_host *host);
         void    (*card_event)(struct mmc_host *host);
+
+        /*
+         * Optional callback to support controllers with HW issues for multiple
+         * I/O. Returns the number of supported blocks for the request.
+         */
+        int     (*multi_io_quirk)(struct mmc_card *card,
+                                  unsigned int direction, int blk_size);
 };
 
 struct mmc_card;