This Thinkpad T420s had been running squeeze without issue for some
time, and also wheezy without issue for some time.

In the last couple of months, however, it has taken to hanging every
few days.  Or rather, X hangs; I can still ssh into the system.  But I
can't use the keyboard at all; even Ctrl-Alt-F1 does nothing.  The
mouse pointer moves, but that's IT.

You can see in the logs below that lines about "EQ overflowing" are
logged when this happens.

I have no workaround.  Even restarting the display manager doesn't fix
it.  A reboot is required 100% of the time.

I have been hoping that recent kernel or X upgrades would fix the
issue, but so far no good.

I will do whatever necessary to help debug this.

severity 680514 grave
merge 680514 680515
thanks

A MTA issue caused me to think the first one hadn't gone through.

Hello!

A am having the same issue.

Some differences and further info:

   - The machine is a Thinkpad L420.

   - Very current Wheezy installation.

   - One time, the driver managed to recover from the overflow,
     but usually hangs in the same way as described above:
     Mouse works, but otherwise it's dead.  The log gives up
     printing after 1000 entries.

   - Happens very frequently with SNA AccelMode and with two screens
     a la Zaphod: 2..5 times a day).

   - I switched on "NoAccel" to try to reduce the problem -- without
     any success.

   - Seems to happen more often if the second screen is actually
     attached.  My second screen is then 1920x1200.

   - Seems to happen only after a few hours, so I suspected
     some heat-related problem.  But the laptop is not overly
     hot, so this may just be a coincidence.

   - I have not seen the crash in UXA mode yet (with Xinerama)

   - I use no kernel tweaks (no i915 options and no acpi options),
     it's all the default.
     (Or better: I used to have some tweaks but switched everything
     off again to resolve the crash issue -- without success)

Please find attached the Xlog log file of a crash.

Best regards,
   Henrik

Working on a Lenovo t420, with an external screen attached via the
display port on a docking station.

I've verified this occurs with an external screen attached, both with and
without the primary laptop screen active.  Additionally, I've noticed the
freezes seem to be proximal to the creation or destruction of tooltips.  I
am investigating making a small application to see if I can trigger the
issue with excessive tooltip UI manipulation.

Dear Maintainer,
*** Please consider answering these questions, where appropriate ***

   * What led up to the situation?
   * What exactly did you do (or not do) that was effective (or
     ineffective)?
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   * What outcome did you expect instead?

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Dear Maintainer,
the same issue happens on Lenovo X220 Intel i915 chipset,
Wheezy and 3.2 Kernel running.
The system randomly hangs up after some days, often after
hibernation/suspension. No way to workaround, the only way to recover system is
to force shutdown and reboot, loosing all work.
This shouldn't happen in a stable release of the OS.
Attached is the /var/log/Xorg.0.log.old file.
Hope to see this issue fixed as soon as possible, i cannot work
in stability conditions this way.

For info, I am also seeing this with xserver-xorg-video-radeon,
suggesting that the problem is higher up the stack than the
device-specific drivers.

This is with an amd-64 installation of Jessie, fully up-to-date.

Although it's impossible to control the computer from the keyboard,
the mouse pointer can still be moved, but the screen does not respond
to any clicks. It **is** possible to SSH into the machine, but it's
particularly slow (especially noticeable when su-ing to root in order
to perform a clean shutdown). But "top" does not show any process
using a lot of CPU, so it appears not to be due to a runaway process.

Xorg log attached.