Re: [Intel-gfx] [PATCH 3/9] drm/display/dp_mst: Add drm_atomic_get_old_mst_topology_state()

[Imre Deak <imre.deak@intel.com>]

On Thu, Jan 26, 2023 at 08:36:20PM +0200, Ville Syrjälä wrote:
> On Wed, Jan 25, 2023 at 01:48:46PM +0200, Imre Deak wrote:
> > Add a function to get the old MST topology state, required by a
> > follow-up i915 patch.
> > 
> > While at it clarify the code comment of
> > drm_atomic_get_new_mst_topology_state().
> > 
> > Cc: Lyude Paul <lyude@redhat.com>
> > Cc: stable@vger.kernel.org # 6.1
> > Cc: dri-devel@lists.freedesktop.org
> > Signed-off-by: Imre Deak <imre.deak@intel.com>
> > ---
> >  drivers/gpu/drm/display/drm_dp_mst_topology.c | 29 +++++++++++++++++--
> >  include/drm/display/drm_dp_mst_helper.h       |  3 ++
> >  2 files changed, 30 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
> > index ebf6e31e156e0..81cc0c3b1e000 100644
> > --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
> > +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
> > @@ -5362,18 +5362,43 @@ struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_a
> >  }
> >  EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
> >  
> > +/**
> > + * drm_atomic_get_old_mst_topology_state: get old MST topology state in atomic state, if any
> > + * @state: global atomic state
> > + * @mgr: MST topology manager, also the private object in this case
> > + *
> > + * This function wraps drm_atomic_get_old_private_obj_state() passing in the MST atomic
> > + * state vtable so that the private object state returned is that of a MST
> > + * topology object.
> > + *
> > + * Returns:
> > + *
> > + * The old MST topology state, or NULL if there's no topology state for this MST mgr
> > + * in the global atomic state
> > + */
> > +struct drm_dp_mst_topology_state *
> > +drm_atomic_get_old_mst_topology_state(struct drm_atomic_state *state,
> > +				      struct drm_dp_mst_topology_mgr *mgr)
> > +{
> > +	struct drm_private_state *priv_state =
> 
> I would include 'old_' in the variable name to remind the reader what it
> is.

Ok, will change it.

> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> > +		drm_atomic_get_old_private_obj_state(state, &mgr->base);
> > +
> > +	return priv_state ? to_dp_mst_topology_state(priv_state) : NULL;
> > +}
> > +EXPORT_SYMBOL(drm_atomic_get_old_mst_topology_state);
> > +
> >  /**
> >   * drm_atomic_get_new_mst_topology_state: get new MST topology state in atomic state, if any
> >   * @state: global atomic state
> >   * @mgr: MST topology manager, also the private object in this case
> >   *
> > - * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
> > + * This function wraps drm_atomic_get_new_private_obj_state() passing in the MST atomic
> >   * state vtable so that the private object state returned is that of a MST
> >   * topology object.
> >   *
> >   * Returns:
> >   *
> > - * The MST topology state, or NULL if there's no topology state for this MST mgr
> > + * The new MST topology state, or NULL if there's no topology state for this MST mgr
> >   * in the global atomic state
> >   */
> >  struct drm_dp_mst_topology_state *
> > diff --git a/include/drm/display/drm_dp_mst_helper.h b/include/drm/display/drm_dp_mst_helper.h
> > index f5eb9aa152b14..32c764fb9cb56 100644
> > --- a/include/drm/display/drm_dp_mst_helper.h
> > +++ b/include/drm/display/drm_dp_mst_helper.h
> > @@ -868,6 +868,9 @@ struct drm_dp_mst_topology_state *
> >  drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
> >  				  struct drm_dp_mst_topology_mgr *mgr);
> >  struct drm_dp_mst_topology_state *
> > +drm_atomic_get_old_mst_topology_state(struct drm_atomic_state *state,
> > +				      struct drm_dp_mst_topology_mgr *mgr);
> > +struct drm_dp_mst_topology_state *
> >  drm_atomic_get_new_mst_topology_state(struct drm_atomic_state *state,
> >  				      struct drm_dp_mst_topology_mgr *mgr);
> >  struct drm_dp_mst_atomic_payload *
> > -- 
> > 2.37.1
> 
> -- 
> Ville Syrjälä
> Intel