[ltp] Re: Bug#565790: cat /proc/acpi/ibm/video and must press power button

linux-thinkpad@linux-thinkpad.org linux-thinkpad@linux-thinkpad.org
Wed, 27 Jan 2010 11:04:11 +0800

OK, I updated the BIOS. No improvement.
On tty1
$ cat /proc/acpi/ibm/video
status:		supported
lcd:		enabled
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

But doing the same cat(1) command from inside of xwindows leaves the user
helpless. All he can do is hold down the power button to power off and
hope his ext3 journals are OK on the next powerup.

Even doing the above experiment in single user boot, then starting xdm,
with pstree showing only
  |-dbus-daemon --fork --print-pid 5 --print-address 7 --session
  |-dbus-launch --exit-with-session sh /home/jidanni/.xsession
  |   `-bash
  |-pdnsd --daemon -p /var/run/pdnsd.pid -c /usr/share/pdnsd/pdnsd-resolvconf.conf
  |   `-3*[{pdnsd}]
  |-scim-launcher -d -c simple -e all -f x11
  |-scim-panel-gtk --display :0.0 -c simple -d --no-stay
  |   `-{scim-panel-gtk}
  |-udevd --daemon
  |   |-udevd --daemon
  |   `-udevd --daemon
      |-Xorg :0 vt7 -nolisten tcp -dpi 84 -auth /var/lib/xdm/authdir/authfiles/A:0-iyHUkZ
          `-sh /home/jidanni/.xsession
              |   |-icewm
              |   |-icewmbg
              |   `-icewmtray
              |-ssh-agent /usr/bin/ck-launch-session /usr/bin/dbus-launch --exit-with-session sh /home/jidanni/.xsession
              `-xterm -class UXTerm -title uxterm -u8
                      |-mail -s pstree results jidanni
                      `-pstree -aAl
then typing
$ cat /proc/acpi/ibm/video
into an xterm, or hitting v on that file in emacs' dired, gives the same
dastardly results. Note I am not root here when I read it. Sure, I don't
go reading /proc/acpi/ibm/video every day. But the curious user should
have to resort to the power button if he steps on this landmine.
I don't know why other users don't see the same problem. I'm just
reporting this landmine to you. If you want me to send you the results
of some hardware prober script you send me, I'd be more than happy to.