megaraid scsi driver sets set->nr_maps as 3 if poll_queues is > 0, and blk-mq actually initializes each map's nr_queues as nr_hw_queues, so megaraid driver has to clear READ queue map's nr_queues, otherwise queue map becomes broken if poll_queues is set as non-zero. Fixes: 9e4bec5b2a23 ("scsi: megaraid_sas: mq_poll support") Cc: Kashyap Desai <kashyap.desai@xxxxxxxxxxxx> Cc: sumit.saxena@xxxxxxxxxxxx Cc: chandrakanth.patil@xxxxxxxxxxxx Cc: linux-block@xxxxxxxxxxxxxxx Cc: Hannes Reinecke <hare@xxxxxxx> Reported-by: Guangwu Zhang <guazhang@xxxxxxxxxx> Tested-by: Guangwu Zhang <guazhang@xxxxxxxxxx> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> --- drivers/scsi/megaraid/megaraid_sas_base.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c index c95360a3c186..0917b05059b4 100644 --- a/drivers/scsi/megaraid/megaraid_sas_base.c +++ b/drivers/scsi/megaraid/megaraid_sas_base.c @@ -3195,6 +3195,9 @@ static int megasas_map_queues(struct Scsi_Host *shost) qoff += map->nr_queues; offset += map->nr_queues; + /* we never use READ queue, so can't cheat blk-mq */ + shost->tag_set.map[HCTX_TYPE_READ].nr_queues = 0; + /* Setup Poll hctx */ map = &shost->tag_set.map[HCTX_TYPE_POLL]; map->nr_queues = instance->iopoll_q_count; -- 2.31.1