From: Alex Deucher <alexander.deucher@amd.com>
Date: Tue, 3 Mar 2015 01:42:53 +0000 (-0500)
Subject: drm/radeon: do a posting read in evergreen_set_irq
X-Git-Tag: v3.4.108~107
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0c354d6abb5433f488ed14add656279f4898eed1;p=thirdparty%2Fkernel%2Fstable.git

drm/radeon: do a posting read in evergreen_set_irq

commit c320bb5f6dc0cb88a811cbaf839303e0a3916a92 upstream.

To make sure the writes go through the pci bridge.

bug:
https://bugzilla.kernel.org/show_bug.cgi?id=90741

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
---

diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index 01434ef9e00f1..c5fe79e67ed99 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -3474,6 +3474,9 @@ int evergreen_init(struct radeon_device *rdev)
 		}
 	}
 
+	/* posting read */
+	RREG32(SRBM_STATUS);
+
 	return 0;
 }