Re: External display

[Christoph Lukas <christoph.lukas@gmx.net>]

Hi Chris,

> > 
> > I am using a Dell E6410 notebook running Ubuntu. Most of the time I am
> > running this notebook in a docking station with closed lid and with an
> > external (DVI) monitor attached to the dock.
> > 
> > Running different kernels I see different behaviour regarding the
> > display configuration after boot.
> > 
> > Booting a 2.6.32 based kernel the internal display is turned off, the
> > external display is turned on and running at it's native resolution of
> > 1920x1200. 
> > This is what I would expect.
> 
> Once upon a time we trusted the lid status and reported the internal
> screen as disconnected when the lid was closed. We were beset by bugs
> reporting broken lid status and the LVDS not working. So we gave up.
> Usually between the BIOS and userspace responding to lid notification
> events, the LVDS is turned off when the lid is closed.
> 
> See commit 6e6c822868f113dabe3c33bdd91e883cc28fa11b
> Author: Eric Anholt <eric@anholt.net>
> Date:   Wed Mar 17 13:48:06 2010 -0700
> 
>     drm/i915: Stop trying to use ACPI lid status to determine LVDS connection.
>     
>     I've been getting more and more quirk reports about this.  It seems
>     clear at this point that other OSes are not using this for determining
>     whether the integrated panel should be turned on, and it is not
>     reliable for doing so.  Better to light up an unintended panel than to
>     not light up the only usable output on the system.
>     
>     Signed-off-by: Eric Anholt <eric@anholt.net>
>     Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
> 
> You may want to try:
> 
> diff --git a/drivers/gpu/drm/i915/intel_lvds.c
> b/drivers/gpu/drm/i915/intel_lvds
> index 9795eb5..45b1fe4 100644
> --- a/drivers/gpu/drm/i915/intel_lvds.c
> +++ b/drivers/gpu/drm/i915/intel_lvds.c
> @@ -474,11 +474,9 @@ intel_lvds_detect(struct drm_connector *connector, bool for
>         struct drm_device *dev = connector->dev;
>         enum drm_connector_status status = connector_status_connected;
>  
> -       /* ACPI lid methods were generally unreliable in this generation, so
> -        * don't even bother.
> -        */
> -       if (IS_GEN2(dev) || IS_GEN3(dev))
> -               return connector_status_connected;
> +       /* ACPI lid methods were generally unreliable, so don't even bother. */
> +       if (INTEL_INFO(dev)->gen >= 5 && !acpi_lid_open())
> +               status = connector_status_disconnected;
>  
>         return status;
>  }
> 

thanks for your response and patch. But this patch did not change
anything for me, sorry. The internal display is still turned on when
booting with closed lid.

I would guess this function is only called for lvds displays while the
internal display on the Dell E6410 is an eDP?

I have added a printk just before the conditional and I have never seen
the output in dmesg.



I would not bother too much about using gnome-display-properties (or
xrandr) to turn the internal display off once after login. What I think
is a little bit annouying is that the internal display is turned back on
after each DPMS blanking.


Thanks and Regards,
Christoph