drm/radeon: do a posting read in si_set_irq

commit 0586915ec10d0ae60de5cd3381ad25a704760402 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index 52b64ad285d626b85b0528cdc46f5aa436474022..d21247e9fd1054d32b90bcd5c704c8ed340fc96b 100644 (file)
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -5958,6 +5958,9 @@ int si_irq_set(struct radeon_device *rdev)
 
        WREG32(CG_THERMAL_INT, thermal_int);
 
+       /* posting read */
+       RREG32(SRBM_STATUS);
+
        return 0;
 }