Hello Imre Deak,
Commit ee00f8fbb2b2 ("drm/i915/dp_mst: Fix configuring TUs for a
disconnected stream") from Sep 7, 2026 (linux-next), leads to the
following Smatch static checker warning:
drivers/gpu/drm/i915/display/intel_link_bw.c:69
intel_link_bw_init_limits()
error: we previously assumed 'crtc_state' could be null (see line 67)
drivers/gpu/drm/i915/display/intel_link_bw.c
53 void intel_link_bw_init_limits(struct intel_atomic_state *state,
54 struct intel_link_bw_limits *limits)
55 {
56 struct intel_display *display = to_intel_display(state);
57 enum pipe pipe;
58
59 limits->link_dsc_pipes = 0;
60 limits->bpp_limit_reached_pipes = 0;
61 for_each_pipe(display, pipe) {
62 struct intel_crtc *crtc = intel_crtc_for_pipe(display,
pipe);
63 const struct intel_crtc_state *crtc_state =
64 intel_atomic_get_new_crtc_state(state, crtc);
65 int forced_bpp_x16 = get_forced_link_bpp_x16(state,
crtc);
66
67 if ((state->base.duplicated && crtc_state) ||
^^^^^^^^^^
Check for NULL
68 intel_dp_mst_stream_disconnected(state, crtc)) {
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Possible this also implied crtc_state is non-NULL? It looks more like
intel_dp_mst_stream_disconnected() assumes that crtc_state is non-NULL...
--> 69 limits->max_bpp_x16[pipe] =
crtc_state->max_link_bpp_x16;
^^^^^^^^^^^^
Unchecked dereference.
70 if (intel_dsc_enabled_on_link(crtc_state))
71 limits->link_dsc_pipes |= BIT(pipe);
72 } else {
73 limits->max_bpp_x16[pipe] = INT_MAX;
74 }
75
76 if (forced_bpp_x16)
77 limits->max_bpp_x16[pipe] =
min(limits->max_bpp_x16[pipe], forced_bpp_x16);
78 }
79 }
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regards,
dan carpenter
