From: Alex Deucher <alexander.deucher@amd.com>
Date: Tue, 3 Mar 2015 01:45:24 +0000 (-0500)
Subject: drm/radeon: do a posting read in cik_set_irq
X-Git-Tag: firefly_0821_release~176^2~2198^2~3^2~2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=cffefd9bb31cd35ab745d3b49005d10616d25bdc;p=firefly-linux-kernel-4.4.55.git

drm/radeon: do a posting read in cik_set_irq

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>
Cc: stable@vger.kernel.org
---

diff --git a/drivers/gpu/drm/radeon/cik.c b/drivers/gpu/drm/radeon/cik.c
index 0c993da9c8fb..3e670d344a20 100644
--- a/drivers/gpu/drm/radeon/cik.c
+++ b/drivers/gpu/drm/radeon/cik.c
@@ -7555,6 +7555,9 @@ int cik_irq_set(struct radeon_device *rdev)
 	WREG32(DC_HPD5_INT_CONTROL, hpd5);
 	WREG32(DC_HPD6_INT_CONTROL, hpd6);
 
+	/* posting read */
+	RREG32(SRBM_STATUS);
+
 	return 0;
 }