[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 <mak...@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