drm/amdgpu/vcn2.5: Remove old DPG workaround

SCRATCH2 is used to keep decode wptr as a workaround
which fix a hardware DPG decode wptr update bug for
vcn2.5 beforehand.
Signed-off-by: James Zhu <James.Zhu@amd.com>
Reviewed-by: Leo Liu <leo.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/vcn_v2_5.c

@@ -1453,11 +1453,6 @@ static int vcn_v2_5_pause_dpg_mode(struct amdgpu_device *adev,
 				WREG32_SOC15(VCN, inst_idx, mmUVD_RB_WPTR2, lower_32_bits(ring->wptr));
 				fw_shared->multi_queue.encode_lowlatency_queue_mode &= ~FW_QUEUE_RING_RESET;
 
-				fw_shared->multi_queue.decode_queue_mode |= FW_QUEUE_RING_RESET;
-				WREG32_SOC15(VCN, inst_idx, mmUVD_RBC_RB_WPTR,
-					   RREG32_SOC15(VCN, inst_idx, mmUVD_SCRATCH2) & 0x7FFFFFFF);
-				fw_shared->multi_queue.decode_queue_mode &= ~FW_QUEUE_RING_RESET;
-
 				/* Unstall DPG */
 				WREG32_P(SOC15_REG_OFFSET(VCN, inst_idx, mmUVD_POWER_STATUS),
 					   0, ~UVD_POWER_STATUS__STALL_DPG_POWER_UP_MASK);
@@ -1519,10 +1514,6 @@ static void vcn_v2_5_dec_ring_set_wptr(struct amdgpu_ring *ring)
 {
 	struct amdgpu_device *adev = ring->adev;
 
-	if (adev->pg_flags & AMD_PG_SUPPORT_VCN_DPG)
-		WREG32_SOC15(VCN, ring->me, mmUVD_SCRATCH2,
-			lower_32_bits(ring->wptr) | 0x80000000);
-
 	if (ring->use_doorbell) {
 		adev->wb.wb[ring->wptr_offs] = lower_32_bits(ring->wptr);
 		WDOORBELL32(ring->doorbell_index, lower_32_bits(ring->wptr));