[Bug 1385089] Re: keyboard sometimes doesn't respond at login

[Steve Langasek]

On Sat, Oct 25, 2014 at 01:01:17AM -0000, diehard67 wrote:
> the only changes were to work around this, adding sleep 2 before exec
> lightdm in /etc/init/lightdm.conf

> I know lightdm.conf  calls plymouth quit before running lightdm itself

Except that it doesn't do that at all.  It only calls 'plymouth quit'
explicitly when either 'text' has been passed on the kernel commandline (an
option that's used to suppress the graphical login and give users a text
login only), or if the target runlevel for the system is single user mode
(and I'm not sure why it does this at all, that may be a bug).

> but I suspect it is not done quitting when lightdm starts running.

And that's fine, because what lightdm does is call 'plymouth quit
--retain-splash' internally before it launches the X server.  This should
work reliably unless there is something causing plymouth to be started only
/after/ lightdm gets to this point.  

> truth be told I have no idea what to look at or how to get more info, if
> there some way to get plymouth, lightdm, x and the kernel to give me
> detailed logs during boot?????

You can get debugging logs out of plymouth by booting with
<plymouth:debug=file:/var/log/plymouth-debug.log>.  X and lightdm logs are
already available under /var/log/lightdm, and the kernel log is at
/var/log/kern.log.

It would indeed be helpful if you could attach these logs corresponding to a
boot that exhibited the problem.

> I should also mention my sisters netbook is not a particularly fast system
> asus eeepc x101ch

Machine specifications should not matter here, except to the extent that a
slower machine will have a bigger window in which a race can happen.

> GRUB_CMDLINE_LINUX="i915.i915_enable_rc6=1 i915.i915_enable_fbc=1
i915.semaphores=1"

However, I wonder about this.  This is an awful lot of module options
overriding the default behavior of the graphics card; I can certainly see
this triggering bugs in the plymouth/lightdm hand-off.  Do you know why
these options are here?  What happens when booting without these options?

> rc.local
> #!/bin/sh 
[...]
> killall plymouthd

This certainly concerns me.  Was this added *only* to work around the lack
of keyboard in the greeter?  That's certainly not the expected way to shut
down plymouthd, and using 'killall' to end the process definitely *does*
have a race because signals are asynchronous.  At minimum, you should be
using 'service plymouth stop' to ensure plymouth is actually stopped before
you then try to start lightdm...

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https://bugs.launchpad.net/bugs/1385089

Title:
  keyboard sometimes doesn't respond at login

Status in “plymouth” package in Ubuntu:
  Incomplete

Bug description:
  I have tried diferant display managers (kdm nd lightdm) both are
  effected sometims whn my sister turns on her netbook she can't type in
  her password untill she puts th cmpute to sleep and wakes it up again,
  this seems to be randome, from what I have been able to fine from
  googling all over the place plymouth is to blame for this, seems to be
  if it is still running when whateverdm starts you will not bable to
  type.

  on my own laptop I have had the same problem and was able to fix it by
  adding a sleep 2 before exec lightdm in /etc/init/lightdm.conf

  my sisters netbook needed  more then that, he delay got to 6 seconds
  long and still wasn't reliable, I had to modify /etc/default/grub to
  ass text after splash then put service lightdm restart in rc.local so
  she could login most of the time.

  she has had the problem in 14.04 and now in 14.10, I have had it sense
  13.04

  ProblemType: Bug
  DistroRelease: Ubuntu 14.10
  Package: xorg 1:7.7+7ubuntu2
  ProcVersionSignature: Ubuntu 3.16.0-23.31-generic 3.16.4
  Uname: Linux 3.16.0-23-generic i686
  ApportVersion: 2.14.7-0ubuntu8
  Architecture: i386
  CurrentDesktop: KDE
  Date: Fri Oct 24 01:43:10 2014
  InstallationDate: Installed on 2014-04-30 (176 days ago)
  InstallationMedia: Kubuntu 14.04 LTS "Trusty Tahr" - Release i386 (20140416.1)
  SourcePackage: xorg
  Symptom: display
  UpgradeStatus: Upgraded to utopic on 2014-10-24 (0 days ago)

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