Subject: Re: video breaks asus-laptop display switching
From: Zhang Rui <rui.zhang@intel.com>
To: Andrei Gaponenko <andrei.gaponenko@cern.ch>
Cc: linux-kernel@vger.kernel.org, corentincj@iksaif.net,
       sziwan@users.sourceforge.net
In-Reply-To: <Pine.LNX.4.64.0712211433030.3239@0-11-d8-ea-8d-5b.dhcp.lbl.gov>
References: <Pine.LNX.4.64.0712211433030.3239@0-11-d8-ea-8d-5b.dhcp.lbl.gov>
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Date: Sat, 22 Dec 2007 15:53:17 +0800
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On Sat, 2007-12-22 at 06:36 +0800, Andrei Gaponenko wrote:
> 
> Hi,
> 
> With 2.6.23 or newer (including 2.6.24-rc6) kernels, writing to the
> /sys/devices/platform/asus-laptop/display file does not do anything:
> 
> Cold boot to single user, then connect an external monitor
> 
> # cat  /sys/devices/platform/asus-laptop/display
> 1
> 
> OK, only the built in LCD is enabled. Try to enable
> the external monitor as well:
> 
> # echo 3 > /sys/devices/platform/asus-laptop/display
> 
> still no image on the external.
> 
> # cat  /sys/devices/platform/asus-laptop/display
> 1
> 
> Still "1", not the "3" we wrote. On the other hand if I boot with an
> external monitor attached, the "display" file always contains 3, even
> after writing 1 there, and there is image on both monitors.
> 
> In 2.6.22 I had to load asus-laptop by hand, but then display
> switching worked nicely. 
> 
> I've noticed that if I do
> 
> # rmmod video
> 
> display switching starts working again with the newer kernels.
> The "video" module was auto-loaded on my system in 2.6.22, but
> did not cause the conflict.
hmm, please "echo 1 > /proc/acpi/video/xxx/DOS" in 2.6.23 and see
if there is any difference.

Thansk,
Rui


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