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

[Imre Deak]

On Thu, Oct 14, 2021 at 12:54:58AM +0300, Ville Syrjälä wrote:
> 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()?

Imo it's better to preserve the connection to ccs in the name, maybe
regarding the cc as a subplane of the ccs plane.

> Shrug. Plenty of different color paint for this one available I think.

Ok with all that, I think the best would be to use the ccs_plane /
ccs_cc_plane names to mean the control plane and clear color plane.
Will change the patch.

--Imre