[PATCH RESEND] drm/amd/display: Check pipe_ctx before it is used

[Ma Ke]

resource_get_otg_master_for_stream() could return NULL, we
should check the return value of 'otg_master' before it is
used in resource_log_pipe_for_stream().

Fixes: 5db346c256bb ("drm/amd/display: update pipe topology log to support subvp")
Signed-off-by: Ma Ke <make24 at iscas.ac.cn>
---
 drivers/gpu/drm/amd/display/dc/core/dc_resource.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index 15819416a2f3..597ca9f369c6 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -2279,6 +2279,8 @@ void resource_log_pipe_topology_update(struct dc *dc, struct dc_state *state)
 					state->stream_status[stream_idx].mall_stream_config.paired_stream);
 			otg_master = resource_get_otg_master_for_stream(
 					&state->res_ctx, state->streams[phantom_stream_idx]);
+			if (!otg_master)
+				continue;
 			resource_log_pipe_for_stream(dc, state, otg_master, stream_idx);
 		}
 	}
-- 
2.25.1