[PATCH weston v6 56/73] compositor-drm: remove unused_connectors array

[Pekka Paalanen]

On Thu, 12 Apr 2018 14:38:01 +0200
Daniel Stone <daniel at fooishbar.org> wrote:

> Hi Pekka,
> 
> On 16 February 2018 at 15:57, Pekka Paalanen <ppaalanen at gmail.com> wrote:
> > Replace the unused_connectors array by iterating through the head list
> > instead. A head that is not enabled (attached to an enabled output) is
> > basically an unused connector.
> >
> > All connectors regardless of their status have a drm_head. This has the
> > nice effect that drm_pending_state_apply_atomic() does not need to
> > re-query the connector properties every time, they can be simply looked
> > up in the drm_head.  
> 
> \o/ Nice!
> 
> Small comment, which also applies to some of the other patches IIRC:
> 
> >         if (b->state_invalid) {
> > +               struct weston_head *head_base;
> > +               struct drm_head *head;
> >                 uint32_t *unused;
> >                 int err;
> >
> >                 /* If we need to reset all our state (e.g. because we've
> >                  * just started, or just been VT-switched in), explicitly
> >                  * disable all the CRTCs and connectors we aren't using. */
> > -               wl_array_for_each(unused, &b->unused_connectors) {
> > -                       struct drm_property_info infos[WDRM_CONNECTOR__COUNT];
> > +               wl_list_for_each(head_base,
> > +                                &b->compositor->head_list, compositor_link) {  
> 
> wl_list_for_each(head, &b->compositor->head_list, base.compositor_link)
> 
> You can get rid of the head_base declaration as well as the cast that way.

Actually I very specifically chose to not do that. I want to keep the
to_drm_head() call, because I envision in the future we will have
several different kinds of heads (virtual maybe) and to_drm_head()
might actually return NULL. Grepping for it will be easy, finding all
the wl_list_for_each(..., base.derived_field) will be hard.

I have been migrating the whole code base towards the explicit calls of
down-cast wrappers and away from the sneaky container_of() double-casts
as I go. This applies to outputs as well.


Thanks,
pq

> 
> That being said, I'm still working through and up to here I've only
> these two comments. Otherwise, so far, very happy to land what's here.
> 
> Cheers,
> Daniel
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