[PATCH 08/36] xfree86: add platform bus hotplug support (v2)

[Dave Airlie]

On Tue, Jul 3, 2012 at 7:18 PM, Keith Packard <keithp at keithp.com> wrote:
> Dave Airlie <airlied at gmail.com> writes:
>
>> no further changes needed, granted I've no idea what drivers other
>> than modesetting will ever do proper hotplug,
>> I suppose I could get a real PCIE dock at some point and hotplug
>> radeon or nouveau, but there is a lot of work
>> kernel side before we could even start on the userspace drivers.
>
> Definitely an adventure for a future time (where we imagine things like
> Thunder Bolt monitors with integrated GPUs).
>
>> with dual-gpu machines even if we power off the discrete we never
>> "unplug" it, its all abstracted in the kernel.
>
> Cool.
>
> If we aren't dealing with hot-plug drivers (aside from modesetting),
> then perhaps the privates issue is far less daunting than we feared.
> The modesetting driver uses no privates, and so we need only get the
> full set of privates allocated from non-hotplug drivers at server
> startup time, leaving the current private allocation system in place.

It uses on private in the prime code for pixmaps, as it has to store
the framebuffer id in it for slave scanout pixmap.

Dave.