From 26d51029575ba3fbdd26c3612c779ee10d0ab5ef Mon Sep 17 00:00:00 2001 From: Marius Vlad Date: Sat, 16 Nov 2019 18:55:17 +0200 Subject: [PATCH] protocol: Add weston-direct-display extension Weston extension to assure clients that the dmabuf buffer will be forwarded directly to the display controller. Signed-off-by: Marius Vlad --- protocol/meson.build | 2 + protocol/weston-direct-display.xml | 82 ++++++++++++++++++++++++++++++ 2 files changed, 84 insertions(+) create mode 100644 protocol/weston-direct-display.xml diff --git a/protocol/meson.build b/protocol/meson.build index 1228d15b..25cea5a8 100644 --- a/protocol/meson.build +++ b/protocol/meson.build @@ -7,6 +7,7 @@ dir_wp_base = dep_wp.get_pkgconfig_variable('pkgdatadir') install_data( [ 'weston-debug.xml', + 'weston-direct-display.xml', ], install_dir: join_paths(dir_data, dir_protocol_libweston) ) @@ -32,6 +33,7 @@ generated_protocols = [ [ 'weston-content-protection', 'internal' ], [ 'weston-test', 'internal' ], [ 'weston-touch-calibration', 'internal' ], + [ 'weston-direct-display', 'internal' ], [ 'xdg-output', 'v1' ], [ 'xdg-shell', 'v6' ], [ 'xdg-shell', 'stable' ], diff --git a/protocol/weston-direct-display.xml b/protocol/weston-direct-display.xml new file mode 100644 index 00000000..274aadd2 --- /dev/null +++ b/protocol/weston-direct-display.xml @@ -0,0 +1,82 @@ + + + + + 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. + + + + + 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'. + + + + + 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'. + + + + + + + Destroys the factory object, but does not affect any other objects. + + + + +