[ltp] Re: How are hotkey and ACPI events handled on newer
Thinkpads (2010+) with 3.x kernels?
vedran alajbegovic
linux-thinkpad@linux-thinkpad.org
Mon, 28 Jan 2013 01:55:39 +0100
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Hello,
i'm also having similar problem. Actually i didn't dig this much to try to
solve this but i'm about to start searching for solution.
My machine is T430 and i desperately need some solution because my battery
is dying after 2 hours now.
This is what i tried so far:
1. I tried to echo various values to
/sys/class/backlight/acpi_video0/brightness
Default value just after boot is 15 so i tried 1. No change.
2. I found on some forum this some tip with adding udev rule so i tried.
And it works after boot but while i'm logged in i can't change brightness..
or i don't know how.
# cat /etc/udev/rules.d/45-backlight.rules
#ACTION=="add", KERNEL=="acpi_video0", SUBSYSTEM=="backlight",
SUBSYSTEMS=="pci", DRIVERS=="nvidia", ATTR{brightness}="2"
Any idea?
On Mon, Jan 21, 2013 at 6:00 PM, Chow Loong Jin <hyperair@debian.org> wrote:
> On 21/01/2013 17:09, Jonas Camillus Jeppesen wrote:
> > xev registers all fn+fx events and fn+end/home both with and without
> gnome
> > running. xev does not register the dedicated volume up/down and mute
> keys.
> >
> > A thing that puzzles me is that the brightness up/down keys
> (fn+end/home) works
> > both with and without gnome whereas other keys (toggle tuochpad for
> example)
> > does not (they are captured by xev but nothing happens). What makes the
> > brightness keys special and what handles those keys compared to what
> handles all
> > the other keys? Whatever handles the brightness keys seem to be running
> > independent of gnome whereas what ever handles the other keys is somehow
> > dependent on gnome. Any ideas?
>
> I think you'll find that the brightness keys are very special, even on the
> firmware level. For example, on the Thinkpad E220S, the F7 and F8 keys
> send out
> duplicate keypresses. Hardware keydown -> software keydown + keyup;
> hardware
> keyup -> software keydown + keyup. Yeah, it's stupid like that.
>
> Incidentally, F7 and F8 are the keys responsible for brightness control on
> that
> Thinkpad (when Fn isn't pressed).
>
> --
> Kind regards,
> Loong Jin
>
> --
> The linux-thinkpad mailing list home page is at:
> http://mailman.linux-thinkpad.org/mailman/listinfo/linux-thinkpad
>
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Hello,<div><br></div><div>i'm also having similar problem. Actually i d=
idn't dig this much to try to solve this but i'm about to start sea=
rching for solution.</div><div><br></div><div>My machine is T430 and i desp=
erately need some solution because my battery is dying after 2 hours now.</=
div>
<div><br></div><div>This is what i tried so far:</div><div><br></div><div>1=
. I tried to echo various values to /sys/class/backlight/acpi_video0/bright=
ness</div><div>Default value just after boot is 15 so i tried 1. No change.=
</div>
<div><br></div><div>2. I found on some forum this some tip with adding udev=
rule so i tried. And it works after boot but while i'm logged in i can=
't change brightness.. or i don't know how.</div><div><br></div>
<div><div># cat /etc/udev/rules.d/45-backlight.rules</div><div>#ACTION=3D=
=3D"add", KERNEL=3D=3D"acpi_video0", SUBSYSTEM=3D=3D&qu=
ot;backlight", SUBSYSTEMS=3D=3D"pci", DRIVERS=3D=3D"nvi=
dia", ATTR{brightness}=3D"2"</div>
</div><div><br></div><div>Any idea?</div><div><br></div><div><br><div class=
=3D"gmail_quote">On Mon, Jan 21, 2013 at 6:00 PM, Chow Loong Jin <span dir=
=3D"ltr"><<a href=3D"mailto:hyperair@debian.org" target=3D"_blank">hyper=
air@debian.org</a>></span> wrote:<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex"><div class=3D"im">On 21/01/2013 17:09, Jonas=
Camillus Jeppesen wrote:<br>
> xev registers all fn+fx events and fn+end/home both with and without g=
nome<br>
> running. xev does not register the dedicated volume up/down and mute k=
eys.<br>
><br>
> A thing that puzzles me is that the brightness up/down keys (fn+end/ho=
me) works<br>
> both with and without gnome whereas other keys (toggle tuochpad for ex=
ample)<br>
> does not (they are captured by xev but nothing happens). What makes th=
e<br>
> brightness keys special and what handles those keys compared to what h=
andles all<br>
> the other keys? Whatever handles the brightness keys seem to be runnin=
g<br>
> independent of gnome whereas what ever handles the other keys is someh=
ow<br>
> dependent on gnome. Any ideas?<br>
<br>
</div>I think you'll find that the brightness keys are very special, ev=
en on the<br>
firmware level. For example, on the Thinkpad E220S, the F7 and F8 keys send=
out<br>
duplicate keypresses. Hardware keydown -> software keydown + keyup; hard=
ware<br>
keyup -> software keydown + keyup. Yeah, it's stupid like that.<br>
<br>
Incidentally, F7 and F8 are the keys responsible for brightness control on =
that<br>
Thinkpad (when Fn isn't pressed).<br>
<span class=3D"HOEnZb"><font color=3D"#888888"><br>
--<br>
Kind regards,<br>
Loong Jin<br>
</font></span><div class=3D"HOEnZb"><div class=3D"h5"><br>
--<br>
The linux-thinkpad mailing list home page is at:<br>
<a href=3D"http://mailman.linux-thinkpad.org/mailman/listinfo/linux-thinkpa=
d" target=3D"_blank">http://mailman.linux-thinkpad.org/mailman/listinfo/lin=
ux-thinkpad</a><br>
</div></div></blockquote></div><br></div>
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