drm/radeon: do a posting read in r100_set_irq

[ Upstream commit f957063fee ]

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
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
This commit is contained in:
Alex Deucher 2015-03-02 20:36:26 -05:00 • committed by Sasha Levin
commit 226c62843f