suspend oddities

pgf at pgf at
Wed Jul 30 15:29:34 EDT 2008

deepak wrote:
 > On Jul 30 2008, at 14:17, pgf at was caught saying:
 > > since i'm not sure which of these are known/expected/
 > > alreadyfixed/beingignored, here are a few things i've noticed
 > > with suspend.  i'll trac any that people think should, or comment
 > > existing trac if appropriate.
 > > 
 > > disclaimer:  some of this testing has been on my g1g1 machine,
 > > running 2159, XFCE (not sugar), with a USB keyboard.
 > > 
 > >     - gamepad keypresses aren't ignored during suspend.  whether or
 > >         not the gamepad is selected as a candidate wakeup event
 > >         (via /sys/power/wakeup_events/gamekey), those keys will
 > >         be queued for tty input while we're suspended.  test by
 > >         starting hexdump (or other key capture program), suspending,
 > >         pushing any of the 8 keys on the bezel, and then resuming.
 > >         note that the keys have registered.  (this is/was true in 708
 > >         as well.)
 > The gamekeys go through PS2 so I'm guessing the EC is queeing that event for
 > us. I can reproduce the same sort of behaviour with by switching to console 
 > on the XO, sleeping via /sys/power/state on serial console, and then hitting
 > a keyboard key to wake up. On wakeup, the character appears on the shell.  
 > However, I just did the following here:
 > echo 0 > /sys/power/wakeup_events/ps2event
 > echo mem > /sys/power/state
 > hit a key
 > hit power button
 > And I don't see the character on console, which means it did not get
 > queued during suspend when wakeup on keypress is disabled. 
 > How are you trigerring resume?

via the power button.  no console switching.

whoa.  when i try your test, on wakeup i get at least a screenful of
newlines, complete with a screenful of bash prompts right after.  ???


 > (FYI, gamekey has been renamed ps2event in latest kernels)
 > >     - the camera LED flashes while suspended.  suspend the laptop,
 > >         use the touchpad or a keyboard key.  observe camera indicator
 > >         blinking.  also true on 708.
 > The way suspend currently works is that we actually go all the way back to 
 > userland and OHM makes a decision on whether we actually want to wake up 
 > or not based on our current state and what triggered the wakeup. I'm guessing 
 > the flashing is the camera driver resuming the device. If you're running 
 > XFCE on top of our OHM, you should see the same behaviour. The wakeup_event
 > interface was put in place to stop this by allowing OHM to specify when
 > we want to actually be woken up.
 > >     - this got me thinking about wakeups and keypresses in general.
 > >        if we're configured to wake up on keypresses or gamepad
 > >        presses (something i've not seen work yet, btw), then the
 > >        keypress causing the wake should be suppressed.  don't know
 > >        whether that's the case or not.
 > >From both our tests, it does not appear to be the case ATM.  Whether 
 > this is intended or not, someone who's been around longer needs to answer.
 > ~Deepak
 > -- 
 > Deepak Saxena - Kernel Developer - dsaxena at

 paul fox, pgf at

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