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
