Making Fedora work with laptops on docking station with external monitor
pasik at iki.fi
Wed Oct 6 20:32:43 UTC 2010
On Wed, Oct 06, 2010 at 12:33:58PM -0700, Adam Williamson wrote:
> On Wed, 2010-10-06 at 22:03 +0300, Pasi Kärkkäinen wrote:
> > On Tue, Oct 05, 2010 at 11:28:43AM -0700, Adam Williamson wrote:
> > > On Tue, 2010-10-05 at 19:20 +0100, Matthew Garrett wrote:
> > > > On Tue, Oct 05, 2010 at 11:18:32AM -0700, Adam Williamson wrote:
> > > >
> > > > > don't we already have default behaviours based on the lid switch,
> > > > > anyway? So why don't we have this problem with those? IIRC, we default
> > > > > to suspending the system when the lid is closed on battery power - so
> > > > > are we suspending people's systems at random, if those systems have
> > > > > lying lid switches?
> > > >
> > > > Because we only do that on lid state transitions.
> > >
> > > So we could at least cover the case where you plug in an external
> > > monitor, then close the lid? That would be better than nothing. I assume
> > > the problem case is booting with the lid closed and an external monitor
> > > connected.
> > >
> > Exactly, that's the problematic case.
> > When you boot F14 laptop lid closed and only external monitor
> > connected, GDM still appears only on the closed internal LVDS,
> > not on the external monitor where is should be.
> > So the behaviour is clearly wrong.
> > This is on HP laptop with radeon graphics.
> You're missing the nuance of the debate. What I mean by 'problem case'
> is that, according to mjg59, lid sensors don't always actually work
> correctly; there are many documented cases of systems whose lid switches
> report incorrect state, especially at boot. So we can't just say 'always
> enable the external monitor and disable the internal monitor if the lid
> switch says 'closed' and there's an external monitor connected', because
> the lid switch might be lying.
Well.. I think as a default we should trust the lid state.
Buggy drivers should be fixed. Buggy BIOSes should be reported to system vendors.
What's the worst thing that can happen when trusting the ACPI lid state?
Think about this:
- Laptop lid open (so internal lvds enabled), and also external monitor connected.
- lid state is wrong at boot, so it says lid closed.
- Scripts check: "lid closed, external display enabled -> use only external monitor".
That gives you a working setup, you can login using the external display,
and use the system perfectly fine. You can then manually enable the
internal lvds display, or possibly enable some workaround,
as you have a buggy laptop/driver/bios.
That doesn't sound bad at all.
The current situation is far more problematic.
If you the lid state is "closed" and there are no external connected monitors,
then maybe enable the lvds anyway..
Did I miss something?
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