Weston extension to assure clients that the dmabuf buffer will be forwarded directly to the display controller. Signed-off-by: Marius Vlad <marius.vlad@collabora.com>dev
parent
69dcd23c60
commit
26d5102957
@ -0,0 +1,82 @@ |
|||||||
|
<?xml version="1.0" encoding="UTF-8"?> |
||||||
|
<protocol name="weston_direct_display"> |
||||||
|
|
||||||
|
<copyright> |
||||||
|
Copyright © 2019 Collabora Ltd. |
||||||
|
|
||||||
|
Permission is hereby granted, free of charge, to any person obtaining a |
||||||
|
copy of this software and associated documentation files (the "Software"), |
||||||
|
to deal in the Software without restriction, including without limitation |
||||||
|
the rights to use, copy, modify, merge, publish, distribute, sublicense, |
||||||
|
and/or sell copies of the Software, and to permit persons to whom the |
||||||
|
Software is furnished to do so, subject to the following conditions: |
||||||
|
|
||||||
|
The above copyright notice and this permission notice (including the next |
||||||
|
paragraph) shall be included in all copies or substantial portions of the |
||||||
|
Software. |
||||||
|
|
||||||
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
||||||
|
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
||||||
|
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
||||||
|
THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
||||||
|
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
||||||
|
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
||||||
|
DEALINGS IN THE SOFTWARE. |
||||||
|
</copyright> |
||||||
|
|
||||||
|
<interface name="weston_direct_display_v1" version="1"> |
||||||
|
<description summary="weston direct display"> |
||||||
|
Weston extension to instruct the compositor to avoid any import |
||||||
|
of the dmabuf created by 'linux-dmabuf' protocol other than the display |
||||||
|
controller. |
||||||
|
|
||||||
|
Compositors are already going to use direct scan-out as much as possible but |
||||||
|
there's no assurance that while doing so, they won't first import the dmabuf |
||||||
|
in to the GPU. This extension assures the client that the compositor will |
||||||
|
never attempt to import in to the GPU and pass it directly to the display |
||||||
|
controller. |
||||||
|
|
||||||
|
Clients can make use of this extension to pass the dmabuf buffer to the |
||||||
|
display controller, potentially increasing the performance and lowering the |
||||||
|
bandwidth usage. |
||||||
|
|
||||||
|
Lastly, clients can make use of this extension in tandem with content-protection |
||||||
|
one thus avoiding any GPU interaction and providing a secure-content path. |
||||||
|
Also, in some cases, the memory where dmabuf are allocated are in specially |
||||||
|
crafted memory zone which would be seen as an illegal memory access when the |
||||||
|
GPU will attempt to read it. |
||||||
|
|
||||||
|
WARNING: This interface by design might break screenshoting functionality |
||||||
|
as compositing might be involved while doing that. Also, do note, that in |
||||||
|
case the dmabufer provided can't be imported by KMS, the client connection |
||||||
|
will be terminated. |
||||||
|
|
||||||
|
WARNING: This extension requires 'linux-dmabuf' protocol and |
||||||
|
'zwp_linux_buffer_params_v1' be already created by 'zwp_linux_buffer_v1'. |
||||||
|
</description> |
||||||
|
|
||||||
|
<request name="enable"> |
||||||
|
<description summary="forward buffer to display controller"> |
||||||
|
This request tells the compositor not to import the dmabuf to the GPU |
||||||
|
in order to bypass it entirely, such that the buffer will be directly |
||||||
|
scanned-out by the display controller. If HW is not capable/or there |
||||||
|
aren't any available resources to directly scan-out the buffer, a |
||||||
|
placeholder should be installed in-place by the compositor. The |
||||||
|
compositor may perform checks on the dmabuf and refuse to create a |
||||||
|
wl_buffer if the dmabuf seems unusable for being used directly. |
||||||
|
|
||||||
|
Assumes that 'zwp_linux_buffer_params_v1' was already created |
||||||
|
by 'zwp_linux_dmabuf_v1_create_params'. |
||||||
|
</description> |
||||||
|
<arg name="dmabuf" type="object" interface="zwp_linux_buffer_params_v1" |
||||||
|
summary="enable direct-display for dmabuf buffer"/> |
||||||
|
</request> |
||||||
|
|
||||||
|
<request name="destroy" type="destructor"> |
||||||
|
<description summary="destroy factory object"> |
||||||
|
Destroys the factory object, but does not affect any other objects. |
||||||
|
</description> |
||||||
|
</request> |
||||||
|
</interface> |
||||||
|
|
||||||
|
</protocol> |
Loading…
Reference in new issue