From: Alex Deucher <alexander.deucher@amd.com>
Date: Tue, 3 Mar 2015 01:41:31 +0000 (-0500)
Subject: drm/radeon: do a posting read in r600_set_irq
X-Git-Tag: v3.4.108~108
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7758b16f963296296384c654a4842fa50912ed97;p=thirdparty%2Fkernel%2Fstable.git

drm/radeon: do a posting read in r600_set_irq

commit 9d1393f23d5656cdd5f368efd60694d4aeed81d3 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/r600.c b/drivers/gpu/drm/radeon/r600.c
index 1555cd6941117..9c7062d970ee7 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -3184,6 +3184,9 @@ int r600_irq_set(struct radeon_device *rdev)
 		WREG32(DC_HOT_PLUG_DETECT3_INT_CONTROL, hpd3);
 	}
 
+	/* posting read */
+	RREG32(R_000E50_SRBM_STATUS);
+
 	return 0;
 }