On 8/6/22, Hoosier, Matt wrote:
> Any idea what’s up with some compositors adding code to infer
> DRM_FORMAT_MOD_LINEAR semantics when the buffer’s modifiers are set to 0?
> Wlroots, for example, added this as a “safety net for drm drivers not
> announcing modifiers”.
>
>
Oh, facepalm. I didn’t even think to look at the numeric value. Sorry for the
confusion.
From: Simon Ser
Sent: Saturday, August 6, 2022 3:10:53 PM
To: Hoosier, Matt
Cc: Pekka Paalanen; dri-devel@lists.freedesktop.org;
wayland-de...@lists.freedesktop.org
Subject:
On Saturday, August 6th, 2022 at 21:56, Hoosier, Matt
wrote:
> Any idea what’s up with some compositors adding code to infer
> DRM_FORMAT_MOD_LINEAR semantics when the buffer’s modifiers are set
> to 0?
What does that mean? A buffer only has a single modifier, and LINEAR == 0.
> Wlroots, for
Hi Pekka,
Thanks. If I paraphrase, I think you’re telling me that gbm_bo_get_modifiers()
== 0 is not strong enough then.
That fits with the notes on the drm_fourcc.h declaration of the linear format
flag:
https://elixir.bootlin.com/linux/latest/source/include/uapi/drm/drm_fourcc.h#L448
Any
On Fri, 5 Aug 2022 12:32:01 +
"Hoosier, Matt" wrote:
> Suppose that I want to map a GPU buffer to the CPU and do image
> analysis on it. I know all the usual cautions about this being a
> poor performance option, etc. But suppose for the moment that the
> use-case requires it.
>
> What's
Suppose that I want to map a GPU buffer to the CPU and do image analysis on it.
I know all the usual cautions about this being a poor performance option, etc.
But suppose for the moment that the use-case requires it.
What's the right set of preconditions to conclude that the buffer is in
