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 0c993da..3e670d3 100644 (file)
--- 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;
 }