[systemd-devel] udev rule not applied after resume from sleep

[Kay Sievers]

On Tue, Dec 10, 2013 at 11:59 PM, Jason A. Donenfeld <Jason at zx2c4.com> wrote:
> I hope this is the right list to ask about udev. I've got a lenovo usb
> keyboard with a trackpoint on it -- essentially an external replica of
> the classic thinkpad keyboard. The trackpoint by default isn't very
> sensitive, so I've got a udev rule that applies the settings I like:
>
> zx2c4 at thinkpad ~ $ cat /etc/udev/rules.d/90-trackpoint.rules
> ACTION=="add", SUBSYSTEM=="hid", DRIVER=="lenovo_tpkbd", \
>         ATTR{sensitivity}="230", \
>         ATTR{press_to_select}="1"
>
> This works well and gets the job done. However, if my computer is in
> sleep mode, and then I plug in the keyboard, and then I resume my
> computer, the rule doesn't get applied. Likewise, if the rule is in
> effect, but then I put my computer to sleep, on resume, the rule isn't
> applied.
>
> Is this by design, and I need to add something to my rule to also
> active on resumption from sleep, or am I hitting some kind of bug?

If the device goes away and comes back during suspend, udev can apply
the rule again.

If the kernel keeps the device around, it's the kernel who needs to
restore the device's state on resume.

You can run "udevadm monitor" before you suspend and look at the
output after resume what's going on. I have no idea how the device in
question is supposed to be handled.

Kay