Re: [Intel-gfx] [PATCH 09/11] drm/i915: Add a platform independent way to check for CCS control planes

Ville Syrjälä
2021-10-13T21:55:04Z

On Thu, Oct 14, 2021 at 12:32:55AM +0300, Imre Deak wrote:
> On Wed, Oct 13, 2021 at 11:45:33PM +0300, Ville Syrjälä wrote:
> > On Wed, Oct 13, 2021 at 11:27:02PM +0300, Ville Syrjälä wrote:
> > > On Thu, Oct 07, 2021 at 11:35:15PM +0300, Imre Deak wrote:
> > > > Future platforms change the location of CCS control planes in CCS
> > > > framebuffers, so add intel_fb_is_rc_ccs_ctrl_plane() to query for these
> > >
> > > Don't we use the term 'ccs_plane' everywhere else?
> > >
> > > > planes independently of the platform. This function can be used
> > > > everywhere instead of is_ccs_plane() (or is_ccs_plane() && !cc_plane()),
> > > > since all the callers are only interested in control planes (and not CCS
> > > > color-clear planes).
> >
> > Hmm. I guess you're changing the terminology across the board?
> > If it's used consistently then no objections from me.
>
> ccs_plane has been used as a generic term for both the "control" and the
> cc plane, or at least I thought of it as such.

The official definition I think is:
CCS == color control surface

So in terms of modifier naming I suppose I tend to think
of it like this:
modifier name has CCS -> color control surface is present
modifier name has CC -> clear color is present

But if we want to make the distinction somehow stronger I was
thinking maybe ccs_aux vs. ccs_cc. But dunno if that just ends up
being more confusing since AUX_DIST is also used for planar scanout
on skl/etc.

Or another way to make it more clear would be to drop the "ccs" part
from the is_ccs_cc_plane() or whatever. But is_cc_plane() is perhaps
also pretty confusing. So could expand it to full on is_clear_color_plane()?
Shrug. Plenty of different color paint for this one available I think.

--
Ville Syrjälä
Intel