megaraid_sas: Add an i/o barrier

A barrier should be added to ensure proper ordering of memory mapped
writes.

Signed-off-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Kashyap Desai <kashyap.desai@broadcom.com>
Acked-by: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index e0b4ca1..5c08568 100644 (file)
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -749,6 +749,7 @@ megasas_fire_cmd_skinny(struct megasas_instance *instance,
               &(regs)->inbound_high_queue_port);
        writel((lower_32_bits(frame_phys_addr) | (frame_count<<1))|1,
               &(regs)->inbound_low_queue_port);
+       mmiowb();
        spin_unlock_irqrestore(&instance->hba_lock, flags);
 }
 

diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c
index d9d0029..98a848b 100644 (file)
--- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
+++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
@@ -204,6 +204,7 @@ megasas_fire_cmd_fusion(struct megasas_instance *instance,
                &instance->reg_set->inbound_low_queue_port);
        writel(le32_to_cpu(req_desc->u.high),
                &instance->reg_set->inbound_high_queue_port);
+       mmiowb();
        spin_unlock_irqrestore(&instance->hba_lock, flags);
 #endif
 }