From a02db0f24cda0f97d9c101df3eafa7ccfc88452e Mon Sep 17 00:00:00 2001 From: Alex Deucher Date: Mon, 2 Mar 2015 20:36:26 -0500 Subject: [PATCH] drm/radeon: do a posting read in r100_set_irq 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 Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/radeon/r100.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c index 46470dd7c710..f9f0e3680d76 100644 --- a/drivers/gpu/drm/radeon/r100.c +++ b/drivers/gpu/drm/radeon/r100.c @@ -743,6 +743,10 @@ int r100_irq_set(struct radeon_device *rdev) tmp |= RADEON_FP2_DETECT_MASK; } WREG32(RADEON_GEN_INT_CNTL, tmp); + + /* read back to post the write */ + RREG32(RADEON_GEN_INT_CNTL); + return 0; } -- 2.34.1