[Intel-gfx] [RFC] VGA hotplug support for i915 kms

[Jesse Barnes]

On Friday, January 16, 2009 5:42 am Jakob Bornecrantz wrote:
> Jesse Barnes wrote:
> > On Wednesday, January 14, 2009 2:14 pm Jesse Barnes wrote:
> >> Here's a work in progress VGA hotplug patch that I've been testing on my
> >> GM45.  I've only tested VGA interrupts so far, but other ports may work
> >> or should be easy to enable.  When a hotplug interrupt is received, the
> >> i915 interrupt handler kicks off a work queue which ends up sending a
> >> uevent. I've deliberately done nothing else; I figure userspace should
> >> decide what to do with the event (ignore it, probe outputs, set up a
> >> cloned or extended configuration, etc.).
> >>
> >> Thoughts or comments?  The passing of the DRM device struct to the work
> >> function is pretty ugly at this point, and could be improved, and
> >> whether hotplug detection is enabled should probably be configurable
> >> since it depends on the outputs being powered enough to detect events.
> >
> > Here's a slightly less revolting version.  I removed all the global
> > variables, and moved to using the system wide work queue rather than an
> > i915 specific one, so things are much cleaner & clearer.
> >
> > Comments?  Userspace will still need to call getresources after receiving
> > a hotplug event, but I think that's better than trying to do something by
> > default in the kernel.
>
> When we only run fbcon we might not be blessed with a clever userspace
> that can add a new monitor to the fb config. Maybe we should run some
> sort of detection code in the intel fb code.
>
> That is my only comment and it is a minor one, so the patch is
>
> Acked-By: Jakob Bornecrantz <jakob at vmware.com>

Thanks for looking, and yeah that's a good point.  We might be able to check 
if the fbcon is the currently active config, and update it.  I'll see about 
that...  We could probably make the default kernel config more explicit too, 
so it's easier to follow the panic, sysrq, and lastclose paths.
-- 
Jesse Barnes, Intel Open Source Technology Center