[PATCH 3.2 079/221] drm/radeon: do a posting read in rs600_set_irq

Ben Hutchings
2015-05-05T02:00:14Z

From: Alex Deucher <alexander.deucher@amd.com>

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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/gpu/drm/radeon/rs600.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/gpu/drm/radeon/rs600.c
+++ b/drivers/gpu/drm/radeon/rs600.c
@@ -576,6 +576,10 @@ int rs600_irq_set(struct radeon_device *
WREG32(R_006540_DxMODE_INT_MASK, mode_int);
WREG32(R_007D08_DC_HOT_PLUG_DETECT1_INT_CONTROL, hpd1);
WREG32(R_007D18_DC_HOT_PLUG_DETECT2_INT_CONTROL, hpd2);
+
+ /* posting read */
+ RREG32(R_000040_GEN_INT_CNTL);
+
return 0;
}