[PATCH] drm/amdgpu: correct wptr initialization for sdma

[Yintian Tao]

If doorbell is used for wptr update, we also need to use it
to initialize wptr to 0.

Change-Id: Ieb31a6726a9ac8d45e51f0370ef5f77dc5ec7c06
Signed-off-by: Yintian Tao <yttao at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c b/drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c
index cfd968e..7b6d3e9 100644
--- a/drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c
@@ -643,8 +643,9 @@ static int sdma_v3_0_gfx_resume(struct amdgpu_device *adev)
 		WREG32(mmSDMA0_GFX_RB_CNTL + sdma_offsets[i], rb_cntl);
 
 		/* Initialize the ring buffer's read and write pointers */
+		ring->wptr = 0;
 		WREG32(mmSDMA0_GFX_RB_RPTR + sdma_offsets[i], 0);
-		WREG32(mmSDMA0_GFX_RB_WPTR + sdma_offsets[i], 0);
+		sdma_v3_0_ring_set_wptr(ring);
 		WREG32(mmSDMA0_GFX_IB_RPTR + sdma_offsets[i], 0);
 		WREG32(mmSDMA0_GFX_IB_OFFSET + sdma_offsets[i], 0);
 
@@ -659,9 +660,6 @@ static int sdma_v3_0_gfx_resume(struct amdgpu_device *adev)
 		WREG32(mmSDMA0_GFX_RB_BASE + sdma_offsets[i], ring->gpu_addr >> 8);
 		WREG32(mmSDMA0_GFX_RB_BASE_HI + sdma_offsets[i], ring->gpu_addr >> 40);
 
-		ring->wptr = 0;
-		WREG32(mmSDMA0_GFX_RB_WPTR + sdma_offsets[i], lower_32_bits(ring->wptr) << 2);
-
 		doorbell = RREG32(mmSDMA0_GFX_DOORBELL + sdma_offsets[i]);
 
 		if (ring->use_doorbell) {
-- 
1.9.1