On 12/19/19 10:29 AM, Mikita Lipski wrote: > > > On 12/18/19 11:15 AM, Aditya Pakki wrote: >> In skip_modeset label within dm_update_crtc_state(), the dc stream >> cannot be NULL. Using BUG_ON as an assertion is not required and >> can be removed. The patch replaces the check with a WARN_ON in case >> dm_new_crtc_state->stream is NULL. >> >> Signed-off-by: Aditya Pakki <pakki001@xxxxxxx> >> --- >> drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c >> index 7aac9568d3be..03cb30913c20 100644 >> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c >> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c >> @@ -7012,7 +7012,7 @@ static int dm_update_crtc_state(struct amdgpu_display_manager *dm, >> * 3. Is currently active and enabled. >> * => The dc stream state currently exists. >> */ >> - BUG_ON(dm_new_crtc_state->stream == NULL); >> + WARN_ON(!dm_new_crtc_state->stream); >> > > Thanks for the patch, but this is NAK from me since it doesn't really do anything to prevent it or fix it. > > If the stream is NULL and it passed this far in the function then something really wrong has happened and the process should be stopped. > > I'm currently dealing with an issue where dm_new_crtc_state->stream is NULL. One of the scenarios could be that driver creates stream for a fake sink instead of failing, that is connected over MST, and calls dm_update_crtc_state to enable CRTC. > >> /* Scaling or underscan settings */ >> if (is_scaling_state_different(dm_old_conn_state, dm_new_conn_state)) >> > Thanks Mikita for your advice regarding the patch. However, would a better error handling in this scenario be helpful ? Clearly, the stream variable is dereferenced in update_stream_scaling_settings would have the same impact as a crash ? _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
