drm/amd/amdgpu: Recovery vcn instance iterate.

The previous logic is recording the amount of valid vcn instances
to use them on SRIOV, it is a hard task due to the vcn accessment is
based on the index of the vcn instance.

Check if the vcn instance enabled before do instance init.

Signed-off-by: Peng Ju Zhou <[e-mail]>
Reviewed-by: Monk Liu <[e-mail]>
Acked-by: Alex Deucher <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/vcn_v3_0.c

···
 	int i;
 
 	if (amdgpu_sriov_vf(adev)) {
-		for (i = 0; i < VCN_INSTANCES_SIENNA_CICHLID; i++)
-			if (amdgpu_vcn_is_disabled_vcn(adev, VCN_DECODE_RING, i))
-				adev->vcn.num_vcn_inst++;
+		adev->vcn.num_vcn_inst = VCN_INSTANCES_SIENNA_CICHLID;
 		adev->vcn.harvest_config = 0;
 		adev->vcn.num_enc_rings = 1;
 
···
 		adev->firmware.fw_size +=
 			ALIGN(le32_to_cpu(hdr->ucode_size_bytes), PAGE_SIZE);
 
-		if ((adev->vcn.num_vcn_inst == VCN_INSTANCES_SIENNA_CICHLID) ||
-		    (amdgpu_sriov_vf(adev) && adev->asic_type == CHIP_SIENNA_CICHLID)) {
+		if (adev->vcn.num_vcn_inst == VCN_INSTANCES_SIENNA_CICHLID) {
 			adev->firmware.ucode[AMDGPU_UCODE_ID_VCN1].ucode_id = AMDGPU_UCODE_ID_VCN1;
 			adev->firmware.ucode[AMDGPU_UCODE_ID_VCN1].fw = adev->vcn.fw;
 			adev->firmware.fw_size +=
···
 				continue;
 
 			ring = &adev->vcn.inst[i].ring_dec;
-			ring->wptr = 0;
-			ring->wptr_old = 0;
-			vcn_v3_0_dec_ring_set_wptr(ring);
-			ring->sched.ready = true;
+			if (amdgpu_vcn_is_disabled_vcn(adev, VCN_DECODE_RING, i)) {
+				ring->sched.ready = false;
+				dev_info(adev->dev, "ring %s is disabled by hypervisor\n", ring->name);
+			} else {
+				ring->wptr = 0;
+				ring->wptr_old = 0;
+				vcn_v3_0_dec_ring_set_wptr(ring);
+				ring->sched.ready = true;
+			}
 
 			for (j = 0; j < adev->vcn.num_enc_rings; ++j) {
 				ring = &adev->vcn.inst[i].ring_enc[j];
-				ring->wptr = 0;
-				ring->wptr_old = 0;
-				vcn_v3_0_enc_ring_set_wptr(ring);
-				ring->sched.ready = true;
+				if (amdgpu_vcn_is_disabled_vcn(adev, VCN_ENCODE_RING, i)) {
+					ring->sched.ready = false;
+					dev_info(adev->dev, "ring %s is disabled by hypervisor\n", ring->name);
+				} else {
+					ring->wptr = 0;
+					ring->wptr_old = 0;
+					vcn_v3_0_enc_ring_set_wptr(ring);
+					ring->sched.ready = true;
+				}
 			}
 		}
 	} else {