linux-kernel - Re: [PATCH v2 0/6] eDP: Support probing eDP panels dynamically instead of hardcoding

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <CAD=FV=UiATFdiYbrAtinmu3BwO=XoOLaWBkypxRwm+GqfQEhyg@mail.gmail.com>
Date:   Thu, 12 Aug 2021 09:00:15 -0700
From:   Doug Anderson <dianders@...omium.org>
To:     Sam Ravnborg <sam@...nborg.org>
Cc:     Thierry Reding <thierry.reding@...il.com>,
        Rob Herring <robh+dt@...nel.org>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        Daniel Vetter <daniel@...ll.ch>,
        dri-devel <dri-devel@...ts.freedesktop.org>,
        linux-arm-msm <linux-arm-msm@...r.kernel.org>,
        Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@...r.kernel.org>, David Airlie <airlied@...ux.ie>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Maxime Ripard <mripard@...nel.org>,
        Steev Klimaszewski <steev@...i.org>,
        Linus W <linus.walleij@...aro.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 0/6] eDP: Support probing eDP panels dynamically
 instead of hardcoding

Hi,

On Thu, Aug 12, 2021 at 2:38 AM Sam Ravnborg <sam@...nborg.org> wrote:
>
> Hi Doug,
> On Mon, Aug 09, 2021 at 03:18:03PM -0700, Doug Anderson wrote:
> > Hi,
> >
> > On Tue, Aug 3, 2021 at 1:41 PM Sam Ravnborg <sam@...nborg.org> wrote:
> > >
> > > Hi Douglas,
> > >
> > > On Fri, Jul 30, 2021 at 02:26:19PM -0700, Douglas Anderson wrote:
> > > > The goal of this patch series is to move away from hardcoding exact
> > > > eDP panels in device tree files. As discussed in the various patches
> > > > in this series (I'm not repeating everything here), most eDP panels
> > > > are 99% probable and we can get that last 1% by allowing two "power
> > > > up" delays to be specified in the device tree file and then using the
> > > > panel ID (found in the EDID) to look up additional power sequencing
> > > > delays for the panel.
> > >
> > > Have you considered a new driver for edp panels?
> > > panel-edp.c?
> > >
> > > There will be some duplicate code from pnale-simple - but the same can
> > > be said by the other panel drivers too.
> > > In the end I think it is better to separate them so we end up with two
> > > less complex panel drivers rather than one do-it-all panel driver.
> > >
> > > I have not looked in detail how this would look like, but my first
> > > impression is that we should split it out.
> >
> > I certainly could, but my argument against it is that really it's the
> > exact same set of eDP panels that would be supported by both drivers.
>
> The idea was to move all eDP panels to the new driver.
>
> My hope it that we can make panel-simple handle a more more narrow set
> of panels. eDP capable displays are IMO not simple panels.

Ah! OK, this makes sense. I can work on this, though it might be a
short while before I can. I think moving all eDP panels out of
panel-simple.c to something like panel-simple-edp.c makes sense. It
will be a patch that will be very hard to cherry-pick anywhere since
it will conflict with everything but it should be doable.


> Likewise DSI capable panels could also be pulled out of panel-simple.

At the moment I haven't done much with DSI panels so I might leave
them in panel-simple for now. I'll evaluate to see how nasty it would
be for me to try this.


> This would continue to duplicate some code - but we have a lot of
> duplicated code across the various panels and the best way forward
> would be to implement more helpers that can be used by the drivers.
>
>         Sam - who is trying to recover form the deadly man flu...

Feel better!

-Doug