From: Alex Deucher <alexander.deucher@amd.com>
Date: Tue, 3 Mar 2015 01:39:56 +0000 (-0500)
Subject: drm/radeon: do a posting read in rs600_set_irq
X-Git-Tag: firefly_0821_release~3679^2~666
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=75ee55cb5901b7dd04f65ce17b5fb5da10d0e9fc;p=firefly-linux-kernel-4.4.55.git

drm/radeon: do a posting read in rs600_set_irq

commit 54acf107e4e66d1f4a697e08a7f60dba9fcf07c3 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/rs600.c b/drivers/gpu/drm/radeon/rs600.c
index ae813fef0818..971d55f73e0c 100644
--- a/drivers/gpu/drm/radeon/rs600.c
+++ b/drivers/gpu/drm/radeon/rs600.c
@@ -636,6 +636,10 @@ int rs600_irq_set(struct radeon_device *rdev)
 	WREG32(R_007D18_DC_HOT_PLUG_DETECT2_INT_CONTROL, hpd2);
 	if (ASIC_IS_DCE2(rdev))
 		WREG32(R_007408_HDMI0_AUDIO_PACKET_CONTROL, hdmi0);
+
+	/* posting read */
+	RREG32(R_000040_GEN_INT_CNTL);
+
 	return 0;
 }