[Mesa-dev] [PATCH 00/14] vl dri3 support for vaapi and vdpau

Axel Davy axel.davy at ens.fr
Wed May 11 15:57:23 UTC 2016


Do you have some local branch to review all at once (it is a bit hard to 
follow with the patches) ?

 From a quick looks, it seems you inspired from the loader dri3 code.

There is also another implementation you can inspire from:
Probably not much more you can get from it.

I haven't checked the code yet, so I don't know if that applies, 
something I have noticed on my tonga with games, is that (non-vsynced) 
apps that get around 45 fps fell like 15 fps (above 50 or below 35 is fine).
I guess this is due to the fact the screen buffer swap waits the buffer 
has finished rendering to execute the swap, and some bad timing when 
hitting 45 fps.
In fact for this specific case with gallium nine, I noticed the problem 
disappear when using thread_submit=true.
thread_submit is an option that was designed for DRI_PRIME case in mind: 
the driver spawns a thread that will wait the buffers we want to present 
are finished rendering before sending them. That solves all the sync 
issues a DRI_PRIME configuration can have.
I think in the case of the problem described, sending buffers that are 
finished rendering prevents the screen buffer swap to have to wait 
another vblank the buffer is rendered.

I guess for video, you really don't want to hit the bad scenario 
described. I'm not sure if you can possibly have the issue or not, but 
that may be something to consider. In all cases, that seems a good thing 
to look at if wanting to implement a good DRI_PRIME support, granting it 
is possible: I don't know the user API, but if the user has guarantee 
for example the updated content will be copied to some pixmap after some 
call, you cannot delay the presentation for that case.


On 11/05/2016 17:06, Leo Liu wrote :
> This series implement DRI3 supports for VA-API and VDPAU. It implements
> supports for DRI3 Open, PixmapFromBuffer, BufferFromPixmap, and for
> PRESENT including PresentPixmap, PresentNotifyMSC, PresentIdleNotify,
> PresentConfigureNotify and PresentCompleteNotify.
> It has been tested with player mpv and vlc with various clips from
> 480p to 4K with framerate from 24 to 60. Also includes window mode
> and fullscreen w/wo compositing manager. The test also includes VA-API
> glx extension.
> There's still some future work like DRI_PRIME different GPU support
> to be added.
> Leo Liu (14):
>    vl: add DRI3 support infrastructure
>    vl/dri3: implement dri3 screen create and destroy
>    vl/dri3: set drawable geometry
>    vl/dri3: register present events
>    vl/dri3: implement flushing for queued events
>    vl/dri3: add back buffers support
>    vl/dri3: implement function for flush frontbuffer
>    vl/dri3: implement funciton for get dirty area
>    vl/dri3: add support for resizing
>    vl/dri3: implement DRI3 BufferFromPixmap
>    st/va: add dri3 support
>    vl/dri3: handle PresentCompleteNotify event
>    vl/dri3: implement functions for get and set timestamp
>    st/vdpau: add dri3 support
>   configure.ac                              |   7 +-
>   src/gallium/auxiliary/Makefile.sources    |   5 +
>   src/gallium/auxiliary/vl/vl_winsys.h      |   5 +
>   src/gallium/auxiliary/vl/vl_winsys_dri3.c | 703 ++++++++++++++++++++++++++++++
>   src/gallium/state_trackers/va/context.c   |   6 +-
>   src/gallium/state_trackers/vdpau/device.c |   6 +-
>   6 files changed, 729 insertions(+), 3 deletions(-)
>   create mode 100644 src/gallium/auxiliary/vl/vl_winsys_dri3.c

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