Linux Plumbers Android+Graphics microconf summary

[Rob Clark]

On Thu, Oct 10, 2013 at 5:09 PM, Daniel Vetter <daniel at ffwll.ch> wrote:
>> * Rob has reposted his atomic modesetting patches, which helps adress
>> part of some of the issues Greg tried to resolve with ADF, although
>> there still is the delta vs full update issue.
>>     http://www.spinics.net/lists/dri-devel/msg46413.html
>
> I've read up your excellent lwn write-up and tbh I don't understand why
> this is an issue - userspace can always opt to emit the full state if it
> wants to. And drm already keeps all the properties around somewhere (afaik
> at least) so I don't think drivers have to keep track of that much stuff.

it isn't actually an issue..

Or rather, it would simplify the kernel part to only support the "full
state update" model.. but in a post-x11 linux userspace world, that
isn't really an option for us, since we are moving away from hw
specfic userspace component talking to KMS and "full state" includes
things which are hw specific.

But if you support delta-update then you can support a userspace which
either does full updates or delta updates.  The direction I'm going w/
atomic ioctl... well, it is not as simple as ADF but most of the hard
work is done by the atomic helpers rather than each driver.

BR,
-R