[hardy] sync hangs, stopping suspend

[Jan-Philipp Litza]

When I suspend my laptop, it sometimes hangs with a blank screen and a flashing cursor in the upper left corner. The system still responds and I can use the keyboard to get back to X, use it as normal and so on, but it won't suspend (and the suspend led doesn't stop blinking). It seems as if the sync process, automatically executed by pm-utils, hangs in D state (and as such isn't even killable) and stops the system from suspending. When trying to shutdown after this incident, it won't finish the process as well and remain turned on. I waited for at least 6 hours for the process to finish.

Regrettably, I am not sure when this problem occured the first time. I am sure it wasn't there in Gutsy (at least I didn't notice, there were other issues with suspend), it only appeared after the update to Hardy, maybe after I bought and installed my external harddrive.

Also, I cannot imagine that this problem is specific to suspending but could occur in other situations as well. I only noticed it while suspending until now because I rarely shut my laptop down, reboot it or unmount my external drive. I didn't have this problem with unmounting flash sticks or something either.

I reported it for the linux package as sync only tells the kernel to flush the write cache as far as I know.

For the records: I use an up-to-date Ubuntu Hardy 8.04.1 with a 2.6.24.19.21 linux-generic kernel.

$ uname -a
Linux deadbook 2.6.24-19-generic #1 SMP Wed Jun 18 14:43:41 UTC 2008 i686 GNU/Linux

$ cat /proc/version_signature
Ubuntu 2.6.24-19.34-generic

dmesg output will be handed in as soon as the bug occurs again I am not so stupid and hardreset the laptop, lspci -vvnn attached, I can deliver /var/log/syslog as well if you're interested, but there really isn't anything helpful.

[Leann Ogasawara (leannogasawara)]

There hasn't been any recent activity in this bug report and we were wondering if this is still an issue? The Ubuntu kernel team is actively working on the upcoming Intrepid Ibex 8.10 release. If you could please test the latest Alpha release for Intrepid it would be much appreciated - http://www.ubuntu.com/testing . Please let us know your results. If the issue still exists, please also provide the appropriate debugging information as outlined at https://wiki.ubuntu.com/KernelTeamBugPolicies . Thanks in advance.

[Leann Ogasawara (leannogasawara)]

The Ubuntu Kernel Team is planning to move to the 2.6.27 kernel for the upcoming Intrepid Ibex 8.10 release. As a result, the kernel team would appreciate it if you could please test this newer 2.6.27 Ubuntu kernel. There are one of two ways you should be able to test:

1) If you are comfortable installing packages on your own, the linux-image-2.6.27-* package is currently available for you to install and test.

--or--

2) The upcoming Alpha5 for Intrepid Ibex 8.10 will contain this newer 2.6.27 Ubuntu kernel. Alpha5 is set to be released Thursday Sept 4. Please watch http://www.ubuntu.com/testing for Alpha5 to be announced. You should then be able to test via a LiveCD.

Please let us know immediately if this newer 2.6.27 kernel resolves the bug reported here or if the issue remains. More importantly, please open a new bug report for each new bug/regression introduced by the 2.6.27 kernel and tag the bug report with 'linux-2.6.27'. Also, please specifically note if the issue does or does not appear in the 2.6.26 kernel. Thanks again, we really appreicate your help and feedback.

[Jan-Philipp Litza (jplitza)]

I upgraded to Intrepid yesterday, and I already thought that the bug vanished because I was able to suspend some times without problems, but now this exact bug reoccured, so it isn't fixed yet. I still have no clue what causes the sync to last forever...

[mehturt (mehturt)]

I have the exact same problem on my Dell D630, Ubuntu 8.10.
$ uname -a
Linux liptak-laptop 2.6.27-10-generic #1 SMP Fri Nov 21 19:19:18 UTC 2008 x86_64 GNU/Linux

[Jan-Philipp Litza (jplitza)]

By the way, the problem still exists for me in Jaunty, completely independant of my external harddrive being attached or not.

[Janick (janickc)]

Problem still exists in Karmic:
uname -a:
Linux discostu 2.6.31-19-generic #56-Ubuntu SMP Thu Jan 28 01:26:53 UTC 2010 i686 GNU/Linux

I'm not sure when exactly this happens, its not 100% reproducible. But if so, it seems that also unmounting of the external harddrive fails.

[Brad Figg (brad-figg)]

This bug was filed against a series that is no longer supported and so is being marked as Won't Fix. If this issue still exists in a supported series, please file a new bug.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.