ubuntu-x-swat team mailing list archive

[Chase Douglas <chase.douglas@xxxxxxxxxxxxx>]

This one is tricky because it does look like an input related issue.
However, I believe this is due to nouveau.

We'll leave aside all the messages about posting touch events for now.
The backtrace can be split into two stacks: the deeper frames are the
normal context stack, while the shallower frames are in signal context.
In xserver 1.10 (hopefully 1.11 will switch to pthreads), input events
are enqueued to a queue in the server in signal context.

What has likely occurred is nouveau is deadlocked or spinning in the X
server. The input events are still handled by the signal context
processing. They keep getting enqueued for the server, but the server is
never able to dequeue them because it never gets out of the nouveau code
that is locked up. After a certain number of events, the input queue
overflows. In the past, you used to see just a couple messages about the
queue overflowing. With the new multitouch work, we spit out a warning
any time an input module tries to post a touch update event for a touch
id that never had a corresponding touch begin event. The touch begin
event probably got caught in the queue or discarded due to the overflow.

In summary, I believe this is still a nouveau issue because the
following line in the log shows that the server is locked up and not
processing input events:

[   407.162] [mi] EQ overflowing. The server is probably stuck in an
infinite loop.

As an aside, the next synaptics module upload will disable semi-
multitouch support (bug #723905). You won't see any more multitouch
related log messages without a full multitouch device. Just fyi in case
you update and no longer see those messages.

** Package changed: xserver-xorg-input-synaptics (Ubuntu) => xserver-
xorg-video-nouveau (Ubuntu)

** Changed in: xserver-xorg-video-nouveau (Ubuntu)
   Importance: High => Undecided

** Changed in: xserver-xorg-video-nouveau (Ubuntu)
     Assignee: Chase Douglas (chasedouglas) => (unassigned)

** Summary changed:

- natty synaptics freeze
+ natty nouveau freeze

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https://bugs.launchpad.net/bugs/736412

Title:
  natty nouveau freeze