On Sun, 10 Jun 2012 19:04:10 +0200, Daniel Vetter <daniel at ffwll.ch> wrote: > On Fri, Jun 08, 2012 at 11:23:10PM +0100, Chris Wilson wrote: > > On Sat, 9 Jun 2012 00:22:12 +0200, Daniel Vetter <daniel at 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 at hotmail.com> > > > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=50501 > > > > Signed-off-by: Chris Wilson <chris at 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. > > Well, I don't disagree on doing the whole shebang. The proplem is that the > load-detect code as-is is gen3 only (and maybe gen4, haven't checked > that) - it surely can't work on pch split platforms if half the registers > we use in there are gone. > > Until that is fixed and properly tested on all relevant platforms, we > should be able to help the bug reporters by simply using the edid > detection, but bailing on the load detect stuff for all HAS_HOTPLUG > platforms (as we do now already). I'll whip up a patch. > > For actual load-detect stuff is imo -next material, and I think we should > dodge that bullet until we have an actual bug reporter wanting it ... I can send them one of my monitors that fails to report an EDID to them so that they can put it behind their KVM that breaks autodetection... Coming up with a solution to handling unknown connection status is indeed -next material, so I'm not too concerned if we punt the entire thing so that we can do a thorough job. If we could handle unknown cleanly, it would have prevented a lot of misery over the years with spurious TV detection and the like. -Chris -- Chris Wilson, Intel Open Source Technology Centre
