Re: [PATCH] qxl: add a connector property to denote hotplug should rescan modes.

[Dave Airlie <airlied@gmail.com>]

On Fri, Oct 11, 2013 at 6:21 PM, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Fri, Oct 11, 2013 at 11:05:00AM +1000, Dave Airlie wrote:
>> From: Dave Airlie <airlied@redhat.com>
>>
>> So GNOME userspace has an issue with when it rescans for modes on hotplug
>> events, if the monitor has no EDID it assumes that nothing has changed on
>> EDID as with real hw we'd never have new modes without a new EDID, and they
>> kind off rely on the behaviour now, however with virtual GPUs we would
>> like to rescan the modes and get a new preferred mode on hotplug events
>> to handle dynamic guest resizing (where you resize the host window and the
>> guest resizes with it).
>>
>> This is a simple property we can make userspace watch for to trigger new
>> behaviour based on it, and can be used to replaced EDID hacks in virtual
>> drivers.
>>
>> Signed-off-by: Dave Airlie <airlied@redhat.com>
>
> There's the related problem that we kinda don't tell userspace which
> connectors exactly changed when sending out a hotplug event. We could
> solve both issues with a hotplug_sequence counter that increments on any
> change. Probably more work though ;-)

Its kinda orthogonal problem though, I don't mind reprobing its more for the
case where userspace does nothing when we have no EDID I need to fix.

Dave.