[PATCH v2 12/12] JUST FOR TEST: Add one-shot trigger to update display

[Daniel Vetter]

On Wed, Jul 01, 2015 at 05:01:52PM +0800, Mark Zhang wrote:
> On 07/01/2015 04:36 PM, Daniel Vetter wrote:
> > On Wed, Jul 01, 2015 at 04:21:55PM +0800, Mark Zhang wrote:
> >> This HACK adds a workqueue to refresh the display periodically.
> >> This is used just for testing.
> > 
> > ->dirty is the drm hook you're looking for, it's meant to flush out any
> > frontbuffer rendering. Generic kms clients using the dumb buffers (e.g.
> > fedora boot splash) use this already.
> > 
> 
> Oh... I did a grep in drm source and are you talking about
> "drm_framebuffer_funcs->dirty"? Yeah, that should work for me.. but that
> requires userspace sending IOCTL to trigger, right? Honestly I'm lazy so
> I created this HACK so that I don't need userspace to test.

Yeah userspace needs to send ioctl already after each drawing. Generic
userspace does that already since it's required by qxl, udl, soon i915 and
probably a few others too. fbdev emulation is more annyoing but there's
code to move around in these drivers (qxl seems best to me as a starting
point) too.

Imo without this you shouldn't merge one-shot, at least not enabled by
default.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch