drm/radeon: do a posting read in evergreen_set_irq

commit c320bb5f6dc0cb88a811cbaf839303e0a3916a92 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: Zefan Li <lizefan@huawei.com>

diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index 01434ef9e00f1517e884ea628ef15f9d1d5f867b..c5fe79e67ed992c2caa305a3e02dc87e6ce36e44 100644 (file)
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -3474,6 +3474,9 @@ int evergreen_init(struct radeon_device *rdev)
                }
        }
 
+       /* posting read */
+       RREG32(SRBM_STATUS);
+
        return 0;
 }