You can not select more than 25 topics
			Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
		
		
		
		
		
			
		
			
				
					
					
						
							82 lines
						
					
					
						
							3.9 KiB
						
					
					
				
			
		
		
	
	
							82 lines
						
					
					
						
							3.9 KiB
						
					
					
				<?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>
 | 
						|
 |