[bug report] drm/amd/display: Add MST atomic routines

[Mikita Lipski]

Hi Dan,

The bug has been fixed by the patch "drm/amd/display: Fix unsigned 
variable compared to less than zero" by Gustavo A. R. Silva

Thanks

On 13.11.2019 13:28, Dan Carpenter wrote:
> Hello Mikita Lipski,
> 
> The patch b4c578f08378: "drm/amd/display: Add MST atomic routines"
> from Nov 6, 2019, leads to the following static checker warning:
> 
> 	drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:4870 dm_encoder_helper_atomic_check()
> 	warn: unsigned 'dm_new_connector_state->vcpi_slots' is never less than zero.
> 
> drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c
>    4851          if (!aconnector->port || !aconnector->dc_sink)
>    4852                  return 0;
>    4853
>    4854          mst_port = aconnector->port;
>    4855          mst_mgr = &aconnector->mst_port->mst_mgr;
>    4856
>    4857          if (!crtc_state->connectors_changed && !crtc_state->mode_changed)
>    4858                  return 0;
>    4859
>    4860          if (!state->duplicated) {
>    4861                  color_depth = convert_color_depth_from_display_info(connector, conn_state);
>    4862                  bpp = convert_dc_color_depth_into_bpc(color_depth) * 3;
>    4863                  clock = adjusted_mode->clock;
>    4864                  dm_new_connector_state->pbn = drm_dp_calc_pbn_mode(clock, bpp);
>    4865          }
>    4866          dm_new_connector_state->vcpi_slots = drm_dp_atomic_find_vcpi_slots(state,
>    4867                                                                             mst_mgr,
>    4868                                                                             mst_port,
>    4869                                                                             dm_new_connector_state->pbn);
>    4870          if (dm_new_connector_state->vcpi_slots < 0) {
>                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> Impossible condition.
> 
>    4871                  DRM_DEBUG_ATOMIC("failed finding vcpi slots: %d\n", (int)dm_new_connector_state->vcpi_slots);
>    4872                  return dm_new_connector_state->vcpi_slots;
>    4873          }
>    4874          return 0;
>    4875  }
> 
> regards,
> dan carpenter
> 

-- 
Thanks,
Mikita Lipski
Software Engineer, AMD
mikita.lipski at amd.com