linux-kernel - Re: [PATCH 4/4] arm64: DTS: allwinner: a64: enable ANX6345 bridge on Teres-I

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>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CA+E=qVcpMeFfC0EEZRpp3Hc_yBGFMv6cGKGSQENpUTw_ZH7UwQ@mail.gmail.com>
Date:   Fri, 17 May 2019 08:25:53 -0700
From:   Vasily Khoruzhick <anarsoul@...il.com>
To:     Torsten Duwe <duwe@....de>
Cc:     Maxime Ripard <maxime.ripard@...tlin.com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Thierry Reding <thierry.reding@...il.com>,
        Chen-Yu Tsai <wens@...e.org>,
        Andrzej Hajda <a.hajda@...sung.com>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
        Icenowy Zheng <icenowy@...c.io>,
        Sean Paul <seanpaul@...omium.org>,
        Harald Geyer <harald@...ib.org>,
        dri-devel <dri-devel@...ts.freedesktop.org>,
        devicetree <devicetree@...r.kernel.org>,
        arm-linux <linux-arm-kernel@...ts.infradead.org>,
        linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 4/4] arm64: DTS: allwinner: a64: enable ANX6345 bridge on Teres-I

On Fri, May 17, 2019 at 2:47 AM Torsten Duwe <duwe@....de> wrote:
>
> On Fri, May 17, 2019 at 11:08:45AM +0200, Maxime Ripard wrote:
> > >
> > > So for all current practical purposes, we can assume the Teres-I panel
> > > to be powered properly and providing valid EDID; nothing to worry about
> > > in software.
> >
> > You're creating a generic binding for all the users of that bridge,
> > while considering only the specific case of the Teres-I.
>
> All I'm saying is that _this_ usage is also valid. Nothing keeps other
> users from defining the output panel; on the contrary: the driver at hand
> already considers an _optional_ panel and handles it, conditionally. So
> driver and binding spec are 100% in sync here.

Well, endpoint is not necessarily a panel. It can be another bridge or
connector - that's why panel can be optional in driver. But it don't
think that you can just omit an endpoint.

> This is much more straightforward than requiring an output and making up
> some dummy code and params because it cannot reasonably be handled.
> (Remember, if there is an output, the driver will make calls to the
> "attached device" driver.)

They aren't dummy. Moreover you have to attach backlight somewhere (to
panel) so it can be disabled when output is disabled.

Try 'xrandr --output eDP-1 --off' on teres with your current code and
see that backlight stays on.

>
>         Torsten
>