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
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -749,6 +749,7 @@
&(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);
}