linux-kernel - Re: [PATCH] drm/sun4i: Use vi plane as primary

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-next>] [day] [month] [year] [list]

Message-ID: <20190920061800.65sm6jth2afatsvl@gilmour>
Date:   Fri, 20 Sep 2019 08:18:00 +0200
From:   Maxime Ripard <mripard@...nel.org>
To:     Roman Stratiienko <roman.stratiienko@...ballogic.com>
Cc:     Jernej Škrabec <jernej.skrabec@...l.net>,
        linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org
Subject: Re: [PATCH] drm/sun4i: Use vi plane as primary

Hi,

On Thu, Sep 19, 2019 at 11:03:26PM +0300, Roman Stratiienko wrote:
> Actually, I beleive this is True solution, and current one is wrong.  Let
> me explain why.
>
> De2. 0 was designed to match Android hwcomposer hal requirements IMO.
> You can easily agree with this conclusion by comparing Composer HAL and
> De2. 0 hardware manuals.
>
> I faced at least 4 issues when try to run Android using the mainline kernel
> sun8i mixer implementation. Current one, missing pixel formats (my previous
> patch), missing plane alpha and rotation properties. I plan to fix it and
> also send appropriate solution to the upstream.
>
> To achieve optimal UI performance Android requires at least 4 ui layers to
> make screen composition. Current patch enables 4th plane usable.

Note that you can also get 4 UI planes by enabling more than one UI
layer per channel. You wouldn't be able to use alpha between each
plane of a given channel, but we can use a similar trick than what we
did for the pipes in the sun4i backend.

Maxime

Download attachment "signature.asc" of type "application/pgp-signature" (229 bytes)