[PATCH 3.2 078/221] drm/radeon: do a posting read in r100_set_irq

Ben Hutchings
2015-05-05T01:40:51Z

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

commit f957063fee6392bb9365370db6db74dc0b2dce0a 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: Ben Hutchings <ben@decadent.org.uk>
---
drivers/gpu/drm/radeon/r100.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/gpu/drm/radeon/r100.c
+++ b/drivers/gpu/drm/radeon/r100.c
@@ -688,6 +688,10 @@ int r100_irq_set(struct radeon_device *r
tmp |= RADEON_FP2_DETECT_MASK;
}
WREG32(RADEON_GEN_INT_CNTL, tmp);
+
+ /* read back to post the write */
+ RREG32(RADEON_GEN_INT_CNTL);
+
return 0;
}