[PATCH] drm/amdgpu: Add a read to GFX v9.4.3 ring test

[Lijo Lazar]

Issue a read to confirm the register write before ringing doorbell. With
multiple XCCs there is chance for race condition.

Signed-off-by: Lijo Lazar <lijo.lazar at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/gfx_v9_4_3.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_4_3.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_4_3.c
index a1c2c952d882..5861e4d0eda9 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_4_3.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_4_3.c
@@ -256,6 +256,7 @@ static int gfx_v9_4_3_ring_test_ring(struct amdgpu_ring *ring)
 	xcc_offset = SOC15_REG_OFFSET(GC, 0, regSCRATCH_REG0);
 	scratch_reg0_offset = SOC15_REG_OFFSET(GC, GET_INST(GC, ring->xcc_id), regSCRATCH_REG0);
 	WREG32(scratch_reg0_offset, 0xCAFEDEAD);
+	tmp = RREG32(scratch_reg0_offset);
 
 	r = amdgpu_ring_alloc(ring, 3);
 	if (r)
-- 
2.25.1