drm/amdgpu: record error code when ring test failed

BugLink: http://bugs.launchpad.net/bugs/1621113

commit 1f703e66 upstream.

Otherwise we may miss errors.
Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

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

@@ -288,7 +288,7 @@ void amdgpu_ib_pool_fini(struct amdgpu_device *adev)
 int amdgpu_ib_ring_tests(struct amdgpu_device *adev)
 {
 	unsigned i;
-	int r;
+	int r, ret = 0;
 
 	for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
 		struct amdgpu_ring *ring = adev->rings[i];
@@ -309,10 +309,11 @@ int amdgpu_ib_ring_tests(struct amdgpu_device *adev)
 			} else {
 				/* still not good, but we can live with it */
 				DRM_ERROR("amdgpu: failed testing IB on ring %d (%d).\n", i, r);
+				ret = r;
 			}
 		}
 	}
-	return 0;
+	return ret;
 }
 
 /*