[gentoo-user] Re: Kernel 4.x and (probably) event issues

[Roman Dobosz <gryf73@op.pl>]

On Mon, 7 Mar 2016 11:00:26 +1100
Adam Carter <adamcarter3@gmail.com> wrote:

> > 1. After successful boot, I've noticed, that buttons above the
> > touchpad[1] stopped working. Tried to debug the thing, but they do
> > nothing even under xev or in showkey - seems like they dead. Didn't find
> > anything interesting by searching the net.
> Longshot (since i've had one instance in the last few years where i need to
> rebuild xorg after a kernel update) have you tried rebuilding the
> xf86-input-* packages against the new kernel?

Yep, that was the first thing, right after rebuilding 3rd party
modules, I've done.

I've done a little test with Live USB with some popular desktop
distribution, and it turns out, those buttons doesn't work there
either. Not sure if it's a kernel bug, or something else.

> > 2. This one is more annoying. After boot to the new shiny 4.x kernel,
> > devices connected via the usb seems to have aggressive power safe mode.
> > For example - if I typing for a while everything is fine, if I stop for
> > a couple of seconds, and then start to type, for approximately 2 seconds
> > there is no response from the device, and after that i can type again.
> > Note, that during those 2s no buffering is done, so whatever I'm typing
> > in this short period, is lost. Same goes to the mouse movement and
> > buttons.
> I haven't had much luck with USB power saving working in a useful way and
> leave it off. Strange its been enabled by default for you.
> 
> cat /sys/bus/usb/devices/*/power/control will show you what the current
> settings are.
> 
> The options are on/auto.
> 
> "on" means that the device should be resumed and autosuspend is not allowed.
> 
> so that's what you want. It can blanket set with;
> 
> echo on | tee /sys/bus/usb/devices/*/power/control
> 
> Or you could work out which devices are actually a problem and just "on"
> those particular ones.

Actually, this was very useful. Thank you for the hint. I've created 
simple script which gives me a device and power status next to it. 
I've compared values from the distro I've mentioned above with the 
values I get from the Gentoo system. It turns out that indeed all 
devices are set to "auto". I've noticed either, that I have running 
laptop mode (app-laptop/laptop-mode-tools), which was the one 
responsible for setting all devices to "auto". Will investigate it a
bit further, if laptop-mode was the only one who change those values.

Thanks.

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