linux-kernel - Re: [PATCH] drm: add modifiers for MediaTek tiled formats

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: <CAPj87rMxSbiqyF3AVwT9tBNFkv0oFDb+TtjRqs6ZLMSgW_6KzQ@mail.gmail.com>
Date: Thu, 19 Dec 2024 09:18:59 +0000
From: Daniel Stone <daniel@...ishbar.org>
To: Eric Smith <eric.smith@...labora.com>
Cc: Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, Maxime Ripard <mripard@...nel.org>, 
	Thomas Zimmermann <tzimmermann@...e.de>, David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>, 
	kernel@...labora.com, dri-devel@...ts.freedesktop.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] drm: add modifiers for MediaTek tiled formats

Hey Eric,

On Thu, 19 Dec 2024 at 00:20, Eric Smith <eric.smith@...labora.com> wrote:
> On 18/12/2024 10.33, Daniel Stone wrote:
> >> +/*
> >> + * MediaTek Tiled Modifier
> >> + * This is a tiled layout using tiles of 16x32 pixels in a row-major layout.
> >> + * For chroma planes this becomes 16x16 tiles.
> >> + */
> >> +#define DRM_FORMAT_MOD_MTK_16L_32S_TILE  fourcc_mod_code(MTK, (1ULL << 0))
> > I think this probably wants to be something like the tiling mode
> > defined in AMD/Arm modifiers, i.e. reserve a few bits in the range to
> > select the tile size, rather than using a single bit here.
>
> Thank you for taking the time, and for your suggestions. Are you
> thinking something along the lines of:
>
> [...]

Yeah, that's exactly it. You could even push the boat out and widen
the fields a little bit to give more headroom; if you want to change
the layout because you want to add more flags or whatever, you can
just do what Arm did, and take the top couple of bits as a layout
version or epoch.

Cheers,
Daniel