[ltp] T420 /proc/acpi/ibm/video not working

Timothy Murphy linux-thinkpad@linux-thinkpad.org
Sun, 08 Feb 2015 16:46:15 +0000

On Saturday 07 February 2015 12:14:45 David Woodfall wrote:

> Output:
> # cat /proc/acpi/ibm/video
> status:         supported
> lcd:            disabled
> crt:            disabled
> dvi:            disabled
> auto:           disabled
> commands:       lcd_enable, lcd_disable
> commands:       crt_enable, crt_disable
> commands:       dvi_enable, dvi_disable
> commands:       auto_enable, auto_disable
> commands:       video_switch, expand_toggle

I get the same output on my T520 under Fedora-21/KDE
in /proc/acpi/ibm/video.
But I have no idea what it means.
How does one give the command lcd_enable, for example,
and what effect does it have?

Timothy Murphy  
gayleard /at/ eircom.net
School of Mathematics, Trinity College, Dublin