From: Tomas Henzl <thenzl@redhat.com>
Date: Thu, 24 May 2018 15:12:46 +0000 (+0200)
Subject: scsi: mpt3sas: Add an I/O barrier
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=10ee1f2206a3f5aa869bede4b7505b24203a7715;p=linux.git

scsi: mpt3sas: 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>
Acked-by: Chaitra P B <chaitra.basappa@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 61f93a1349563..293f04119ebae 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -3344,6 +3344,7 @@ _base_mpi_ep_writeq(__u64 b, volatile void __iomem *addr,
 	spin_lock_irqsave(writeq_lock, flags);
 	writel((u32)(data_out), addr);
 	writel((u32)(data_out >> 32), (addr + 4));
+	mmiowb();
 	spin_unlock_irqrestore(writeq_lock, flags);
 }