drm/amd/amdgpu: Fix srbm_indexing in init/inactive hqd code

Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c

@@ -5462,6 +5462,7 @@ static void gfx_v8_0_inactive_hqd(struct amdgpu_device *adev,
 {
 	int i;
 
+	mutex_lock(&adev->srbm_mutex);
 	vi_srbm_select(adev, ring->me, ring->pipe, ring->queue, 0);
 	if (RREG32(mmCP_HQD_ACTIVE) & CP_HQD_ACTIVE__ACTIVE_MASK) {
 		WREG32_FIELD(CP_HQD_DEQUEUE_REQUEST, DEQUEUE_REQ, 2);
@@ -5471,6 +5472,8 @@ static void gfx_v8_0_inactive_hqd(struct amdgpu_device *adev,
 			udelay(1);
 		}
 	}
+	vi_srbm_select(adev, 0, 0, 0, 0);
+	mutex_unlock(&adev->srbm_mutex);
 }
 
 static int gfx_v8_0_pre_soft_reset(void *handle)
@@ -5576,11 +5579,13 @@ static int gfx_v8_0_soft_reset(void *handle)
 static void gfx_v8_0_init_hqd(struct amdgpu_device *adev,
 			      struct amdgpu_ring *ring)
 {
+	mutex_lock(&adev->srbm_mutex);
 	vi_srbm_select(adev, ring->me, ring->pipe, ring->queue, 0);
 	WREG32(mmCP_HQD_DEQUEUE_REQUEST, 0);
 	WREG32(mmCP_HQD_PQ_RPTR, 0);
 	WREG32(mmCP_HQD_PQ_WPTR, 0);
 	vi_srbm_select(adev, 0, 0, 0, 0);
+	mutex_unlock(&adev->srbm_mutex);
 }
 
 static int gfx_v8_0_post_soft_reset(void *handle)