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From: Doug Anderson <dianders@chromium.org>
Date: Tue, 27 Feb 2024 08:50:23 -0800
Message-ID: <CAD=FV=W+fRDOS01LKkeq-k12mj6jnFu5LOc9jAE3LA5w2ubo5g@mail.gmail.com>
Subject: Re: [PATCH 1/2] drm_edid: Add a function to get EDID base block
To: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>, Neil Armstrong <neil.armstrong@linaro.org>, 
	Jessica Zhang <quic_jesszhan@quicinc.com>, Sam Ravnborg <sam@ravnborg.org>, 
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>, Maxime Ripard <mripard@kernel.org>, 
	Thomas Zimmermann <tzimmermann@suse.de>, David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>, 
	dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
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Hi,

On Tue, Feb 27, 2024 at 1:09=E2=80=AFAM Jani Nikula <jani.nikula@linux.inte=
l.com> wrote:
>
> On Fri, 23 Feb 2024, Hsin-Yi Wang <hsinyi@chromium.org> wrote:
> > It's found that some panels have variants that they share the same pane=
l id
> > although their EDID and names are different. Besides panel id, now we n=
eed
> > the hash of entire EDID base block to distinguish these panel variants.
> >
> > Add drm_edid_get_base_block to returns the EDID base block, so caller c=
an
> > further use it to get panel id and/or the hash.
>
> Please reconsider the whole approach here.
>
> Please let's not add single-use special case functions to read an EDID
> base block.
>
> Please consider reading the whole EDID, using the regular EDID reading
> functions, and use that instead.
>
> Most likely you'll only have 1-2 blocks anyway. And you might consider
> caching the EDID in struct panel_edp if reading the entire EDID is too
> slow. (And if it is, this is probably sensible even if the EDID only
> consists of one block.)

That makes a lot of sense! Not quite sure why I didn't just read the
whole EDID in the first place when trying to get the panel ID.

-Doug