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: Zefan Li <lizefan@huawei.com>

diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index e710073923e978e639d08e2729bd2ce7b12c40e7..068b21f0d7df837cb8371a959288e6a67d8cc42a 100644 (file)
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -4126,6 +4126,9 @@ int si_init(struct radeon_device *rdev)
                return -EINVAL;
        }
 
+       /* posting read */
+       RREG32(SRBM_STATUS);
+
        return 0;
 }