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-Url: http://git.mmlx.us/?a=commitdiff_plain;h=96e612822a99f6a19f2a5a9e3405da7123a762d6;p=linux-edison.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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index 4cf21ec1abe..90b007594e3 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -3459,6 +3459,9 @@ int r600_init(struct radeon_device *rdev)
 		rdev->accel_working = false;
 	}
 
+	/* posting read */
+	RREG32(R_000E50_SRBM_STATUS);
+
 	return 0;
 }