[PATCH 09/11] drm/dp_mst: Add drm_dp_mst_aux_for_parent()

[Imre Deak]

On Wed, Mar 27, 2024 at 02:30:53PM +0530, Nautiyal, Ankit K wrote:
> 
> On 3/21/2024 1:41 AM, Imre Deak wrote:
> > Add a function to get the AUX device of the parent of an MST port, used
> > by a follow-up i915 patch in the patchset.
> > 
> > Cc: Lyude Paul <lyude at redhat.com>
> > Cc: dri-devel at lists.freedesktop.org
> > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > ---
> >   drivers/gpu/drm/display/drm_dp_mst_topology.c | 16 ++++++++++++++++
> >   1 file changed, 16 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
> > index 6bd471a2266ce..d70f7de644371 100644
> > --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
> > +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
> > @@ -6004,6 +6004,22 @@ static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port)
> >   	return false;
> >   }
> > +/**
> > + * drm_dp_mst_aux_for_parent() - Get the AUX device for an MST port's parent
> > + * @port: MST port whose parent's AUX device is returned
> > + *
> > + * Return the AUX device for @port's parent or NULL if port's parent is the
> > + * root port.
> > + */
> > +struct drm_dp_aux *drm_dp_mst_aux_for_parent(struct drm_dp_mst_port *port)
> > +{
> > +	if (!port->parent || !port->parent->port_parent)
> > +		return NULL;
> > +
> > +	return &port->parent->port_parent->aux;
> > +}
> > +EXPORT_SYMBOL(drm_dp_mst_aux_for_parent);
> 
> As mentioned in previous patch, the declaration of this in the header,
> got included in previous patch.

Yes thanks, the header change should've been in this patch, will move it here
(while applying the patches if nothing else comes up).

> Regards,
> 
> Ankit
> 
> > +
> >   /**
> >    * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC
> >    * @port: The port to check. A leaf of the MST tree with an attached display.