Exposing monitor layout to desktop managers

[Thomas Hellstrom]

On 12/11/2014 12:57 PM, Dave Airlie wrote:
> On 11 December 2014 at 20:58, Thomas Hellstrom <thomas at shipmail.org> wrote:
>> Hi!
>>
>> I'd like to have a standard / generic way of exposing virtual monitor
>> layout to desktop managers. This would then serve as a *hint* to those
>> managers to set the desktop up accordingly.
>>
>> Of course, this is mostly for virtual hardware, since without
>> accelerometers, gyros and gps positioners on monitors, the kernel
>> wouldn't be able to know where the user put his monitors.
>>
>> One could argue that this is purely user-space policy, but since those
>> managers monitor the kms interface anyway it would be a convenient place
>> to expose this information.
>>
>> One idea would to place the x,y location in an output property.
>>
>> Another idea would be to send new layout for all connected output as a
>> drm event.
>>
> Have a look at drm-next, we added a suggested x/y property to connectors,
> and qxl support for it.
>
> I think the spice guys added mutter support for it as well and qxl
> X.org driver passes through the property.
>
> Dave.

Dave,

Did the hotplug_mode_update_property end up being used by user-space? In
that case, should we move it to drm_device::mode_config?

Thanks,
Thomas