Re: [PATCH] drm/i915/crt: Do not rely upon the HPD presence pin

[Chris Wilson <chris@chris-wilson.co.uk>]

On Sat, 9 Jun 2012 00:22:12 +0200, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Thu, May 31, 2012 at 01:08:53PM +0100, Chris Wilson wrote:
> > Whilst most monitors do wire up the HPD presence pin, it seems quite a
> > few KVM do not. Therefore if we simply rely on the HPD pin being
> > asserted to indicate a connected monitor we fail miserable, so fall back
> > to performing a DCC query for the EDID.
> > 
> > Reported-and-tested-by: Matthieu LAVIE <boiteamadmax@hotmail.com>
> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=50501
> > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> 
> Ok, this blew up ... Can you please resend, with Dave's suggestion for a
> rectified commit message & comment and with a check added such that we
> don't try to do load_detect on HAS_HOTPLUG machines - I guess it doesn't
> work too well.

I disagree, if we cannot trust the hw autodetection, then we know that
there are monitors/kvm that do not report an EDID and so we need to do
the whole shebang. Which will continue to annoy Linus since his machine
is behaving as expected given the circumstances.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre