On Wed, Jun 03, 2020 at 10:45:23AM +0000, Simon Ser wrote: > In update_output_state, the link-status property was reset to GOOD to > ensure legacy drmModeSetCrtc re-trains the link. However this auto-reset > is also performed on an atomic commit without ALLLOW_MODESET. If a
I didn't think udate_output_state() was getting called for non-legacy paths. Where is that coming from? > driver reads link-status to figure out whether to re-train the link, > this could cause an atomic commit failure. User-space doesn't expect > such a failure, because commits without ALLOW_MODESET aren't supposed to > fail because of link training issues. > > Change update_output_state to implicitly reset link-status to GOOD only > if ALLOW_MODESET is set. This is the case for legacy drmModeSetCrtc > because drm_atomic_state_init sets it (and is used in > drm_atomic_helper_set_config, called from drm_mode_setcrtc). > > Drivers don't seem to read link-status at the moment -- they seem to > rely on user-space performing a modeset instead. So this shouldn't > result in any change in behaviour, this should only prevent future > failures if drivers start reading link-status. > > Signed-off-by: Simon Ser <cont...@emersion.fr> > Suggested-by: Pekka Paalanen <ppaala...@gmail.com> > Cc: Daniel Vetter <dan...@ffwll.ch> > Cc: Manasi Navare <manasi.d.nav...@intel.com> > --- > drivers/gpu/drm/drm_atomic.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c > index 965173fd0ac2..3d9d9e6f7397 100644 > --- a/drivers/gpu/drm/drm_atomic.c > +++ b/drivers/gpu/drm/drm_atomic.c > @@ -1426,7 +1426,8 @@ static int update_output_state(struct drm_atomic_state > *state, > return ret; > > /* Make sure legacy setCrtc always re-trains */ > - new_conn_state->link_status = DRM_LINK_STATUS_GOOD; > + if (state->allow_modeset) > + new_conn_state->link_status = > DRM_LINK_STATUS_GOOD; > } > } > > -- > 2.26.2 > > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Ville Syrjälä Intel _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
