>-----Original Message----- >From: Hannes Reinecke [mailto:hare@xxxxxxx] >Sent: Friday, November 11, 2016 3:15 PM >To: Martin K. Petersen >Cc: Christoph Hellwig; James Bottomley; Sumit Saxena; linux- >scsi@xxxxxxxxxxxxxxx; Hannes Reinecke; Hannes Reinecke >Subject: [PATCH 5/5] megaraid_sas: add mmio barrier after register writes > >The megaraid_sas HBA only has a single register for I/O submission, which will be >hit pretty hard with scsi-mq. To ensure that the PCI writes have made it across we >need to add a mmio barrier after each write; otherwise I've been seeing spurious >command completions and I/O stalls. > >Signed-off-by: Hannes Reinecke <hare@xxxxxxxx> Acked-by: Sumit Saxena <sumit.saxena@xxxxxxxxxxxx> >--- > drivers/scsi/megaraid/megaraid_sas_fusion.c | 1 + > 1 file changed, 1 insertion(+) > >diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c >b/drivers/scsi/megaraid/megaraid_sas_fusion.c >index aba53c0..729a654 100644 >--- a/drivers/scsi/megaraid/megaraid_sas_fusion.c >+++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c >@@ -196,6 +196,7 @@ inline void megasas_return_cmd_fusion(struct >megasas_instance *instance, > le32_to_cpu(req_desc->u.low)); > > writeq(req_data, &instance->reg_set->inbound_low_queue_port); >+ mmiowb(); > #else > unsigned long flags; > >-- >1.8.5.6 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
