drm/amdgpu: enable software ih ring for vega20 ih block

software ih ring will be used as a workaround
in case hardware ih ring 1 and ring 2 don't work
Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Feifei Xu <Feifei.Xu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/vega20_ih.c

@@ -342,6 +342,9 @@ static int vega20_ih_irq_init(struct amdgpu_device *adev)
 	if (ret)
 		return ret;
 
+	if (adev->irq.ih_soft.ring_size)
+		adev->irq.ih_soft.enabled = true;
+
 	return 0;
 }
 
@@ -539,6 +542,10 @@ static int vega20_ih_sw_init(void *handle)
 	/* initialize ih control registers offset */
 	vega20_ih_init_register_offset(adev);
 
+	r = amdgpu_ih_ring_init(adev, &adev->irq.ih_soft, PAGE_SIZE, true);
+	if (r)
+		return r;
+
 	r = amdgpu_irq_init(adev);
 
 	return r;