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Date:   Tue, 14 Apr 2020 14:34:04 +0200
From:   Daniel Vetter <daniel@ffwll.ch>
To:     Jani Nikula <jani.nikula@linux.intel.com>
Cc:     Simon Ser <contact@emersion.fr>, Yussuf Khalil <dev@pp3345.net>,
        David Airlie <airlied@linux.ie>,
        "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>
Subject: Re: [PATCH 5/5] drm/i915: Replace "Broadcast RGB" with "RGB
 quantization range" property
Message-ID: <20200414123404.GT3456981@phenom.ffwll.local>
Mail-Followup-To: Jani Nikula <jani.nikula@linux.intel.com>,
        Simon Ser <contact@emersion.fr>, Yussuf Khalil <dev@pp3345.net>,
        David Airlie <airlied@linux.ie>,
        "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>
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On Tue, Apr 14, 2020 at 02:21:06PM +0300, Jani Nikula wrote:
> On Tue, 14 Apr 2020, Jani Nikula <jani.nikula@linux.intel.com> wrote:
> > On Mon, 13 Apr 2020, Simon Ser <contact@emersion.fr> wrote:
> >> On Monday, April 13, 2020 11:40 PM, Yussuf Khalil <dev@pp3345.net> wrote:
> >>
> >>> DRM now has a globally available "RGB quantization range" connector
> >>> property. i915's "Broadcast RGB" that fulfils the same purpose is now
> >>> considered deprecated, so drop it in favor of the DRM property.
> >>
> >> For a UAPI point-of-view, I'm not sure this is fine. Some user-space
> >> might depend on this property, dropping it would break such user-space.
> >
> > Agreed.
> >
> >> Can we make this property deprecated but still keep it for backwards
> >> compatibility?
> >
> > Would be nice to make the i915 specific property an "alias" for the new
> > property, however I'm not sure how you'd make that happen. Otherwise
> > juggling between the two properties is going to be a nightmare.
> 
> Ah, the obvious easy choice is to use the property and enum names
> already being used by i915 and gma500, and you have no problem. Perhaps
> they're not the names you'd like, but then looking at the total lack of
> consistency across property naming makes them fit right in. ;)

Yeah if we don't have contradictory usage across drivers when modernizing
these properties, then let's just stick with the names already there. It's
not pretty, but works better since more userspace/internet howtos know how
to use this stuff.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch