[Intel-gfx] [PATCH] Add modesetting pageflip ioctl and corresponding drm event

[Jesse Barnes]

On Thu, 14 May 2009 23:04:51 -0400
Kristian Høgsberg <krh at bitplanet.net> wrote:

> From: Kristian Høgsberg <krh at redhat.com>
> 
> This patch adds a vblank synced pageflip ioctl for to the modesetting
> family of ioctls.  The ioctl takes a crtc and an fb and schedules a
> pageflip to the new fb at the next coming vertical blank event.  This
> feature lets userspace implement tear-free updating of the screen
> contents with hw-guaranteed low latency page flipping.
> 
> The ioctl is asynchronous in that it returns immediately and then
> later notifies the client by making an event available for reading on
> the drm fd. This lets applications add the drm fd to their main loop
> and handle other tasks while waiting for the flip to happen.  The
> event includes the time of the flip, the frame counter and a 64 bit
> opaque token provided by user space in the ioctl.
> 
> Based on initial work and suggestions from
> 	Jesse Barnes <jbarnes at virtuousgeek.org> and
> 	Jakob Bornecrantz <wallbraker at gmail.com>.
> 
> Signed-off-by: Kristian Høgsberg <krh at redhat.com>
> ---

Hey, you didn't even compile this! :)

I'm trying this version out now.  I'll see if I can add the async
set_pipe_base, then start hacking on updates to the dri2-swapbuffers
branches to get it working with userspace.

Thanks,
-- 
Jesse Barnes, Intel Open Source Technology Center