drm/amdgpu:change sequence of SDMA v4 init

must set minor_update.enable before write smaller value
to wptr/doorbell, so for sriov we need set that register
bit in hw_init period.

this could fix the SDMA ring test fail after guest reboot

Signed-off-by: Monk Liu <Monk.Liu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c

@@ -560,8 +560,14 @@ static int sdma_v4_0_gfx_resume(struct amdgpu_device *adev)
 		WREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_GFX_RB_BASE_HI), ring->gpu_addr >> 40);
 
 		ring->wptr = 0;
-		WREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_GFX_RB_WPTR), lower_32_bits(ring->wptr) << 2);
-		WREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_GFX_RB_WPTR_HI), upper_32_bits(ring->wptr) << 2);
+
+		/* before programing wptr to a less value, need set minor_ptr_update first */
+		WREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_GFX_MINOR_PTR_UPDATE), 1);
+
+		if (!amdgpu_sriov_vf(adev)) { /* only bare-metal use register write for wptr */
+			WREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_GFX_RB_WPTR), lower_32_bits(ring->wptr) << 2);
+			WREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_GFX_RB_WPTR_HI), upper_32_bits(ring->wptr) << 2);
+		}
 
 		doorbell = RREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_GFX_DOORBELL));
 		doorbell_offset = RREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_GFX_DOORBELL_OFFSET));
@@ -577,15 +583,23 @@ static int sdma_v4_0_gfx_resume(struct amdgpu_device *adev)
 		WREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_GFX_DOORBELL_OFFSET), doorbell_offset);
 		nbio_v6_1_sdma_doorbell_range(adev, i, ring->use_doorbell, ring->doorbell_index);
 
+		if (amdgpu_sriov_vf(adev))
+			sdma_v4_0_ring_set_wptr(ring);
+
+		/* set minor_ptr_update to 0 after wptr programed */
+		WREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_GFX_MINOR_PTR_UPDATE), 0);
+
 		/* set utc l1 enable flag always to 1 */
 		temp = RREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_CNTL));
 		temp = REG_SET_FIELD(temp, SDMA0_CNTL, UTC_L1_ENABLE, 1);
 		WREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_CNTL), temp);
 
-		/* unhalt engine */
-		temp = RREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_F32_CNTL));
-		temp = REG_SET_FIELD(temp, SDMA0_F32_CNTL, HALT, 0);
-		WREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_F32_CNTL), temp);
+		if (!amdgpu_sriov_vf(adev)) {
+			/* unhalt engine */
+			temp = RREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_F32_CNTL));
+			temp = REG_SET_FIELD(temp, SDMA0_F32_CNTL, HALT, 0);
+			WREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_F32_CNTL), temp);
+		}
 
 		/* enable DMA RB */
 		rb_cntl = REG_SET_FIELD(rb_cntl, SDMA0_GFX_RB_CNTL, RB_ENABLE, 1);
@@ -601,6 +615,11 @@ static int sdma_v4_0_gfx_resume(struct amdgpu_device *adev)
 
 		ring->ready = true;
 
+		if (amdgpu_sriov_vf(adev)) { /* bare-metal sequence doesn't need below to lines */
+			sdma_v4_0_ctx_switch_enable(adev, true);
+			sdma_v4_0_enable(adev, true);
+		}
+
 		r = amdgpu_ring_test_ring(ring);
 		if (r) {
 			ring->ready = false;
@@ -671,8 +690,6 @@ static int sdma_v4_0_load_microcode(struct amdgpu_device *adev)
 			(adev->sdma.instance[i].fw->data +
 				le32_to_cpu(hdr->header.ucode_array_offset_bytes));
 
-		sdma_v4_0_print_ucode_regs(adev);
-
 		WREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_UCODE_ADDR), 0);
 
 
@@ -699,10 +716,10 @@ static int sdma_v4_0_load_microcode(struct amdgpu_device *adev)
  */
 static int sdma_v4_0_start(struct amdgpu_device *adev)
 {
-	int r;
+	int r = 0;
 
 	if (amdgpu_sriov_vf(adev)) {
-		/* disable RB and halt engine */
+		sdma_v4_0_ctx_switch_enable(adev, false);
 		sdma_v4_0_enable(adev, false);
 
 		/* set RB registers */