PanP5 suspend/hibernate CPU bug

[PGScooter]

Hi,

I'm wondering if System 76 has made any progress in getting this bug fixed. A few of us users have tried, see the page here:

http://ubuntuforums.org/showthread.php?t=1458647&page=3

and here for the bug report:
https://bugs.launchpad.net/ubuntu/+s...ls/+bug/364514

The bug seems specific to System 76 hardware, so I don't expect much from Ubuntu developers.

Any progress or new ideas? Thanks

[isantop]

Do you still have the bug in 11.10? We typically focus more of our development effort to the latest release, so if it's something that only affects 10.04, we're not likely to put a lot of effort into it, particularly with 12.04 so close to release.

[PGScooter]

Do you still have the bug in 11.10? We typically focus more of our development effort to the latest release, so if it's something that only affects 10.04, we're not likely to put a lot of effort into it, particularly with 12.04 so close to release.

that sounds like a very reasonable policy. I have the bug in 11.04. The last post on the bug report I linked to says that there is still a bug in 11.10. I would assume that it is also in 12.04, but I will wait until the final release of 12.04 to install it. However, if it would help you a lot and you would put some time into it, then I would be willing to test with earlier versions of 12.04.

[isantop]

Does the workaround in that post work for you to get every back to normal? Also, where are you checking the CPU frequency?

I wouldn't recommend running 12.04 until it's released. I'll see if we have a PanP5 in the shop here and do some testing.

[PGScooter]

Great! Thanks a lot for looking into it. I have 11.04 (the user in the last post has 11.10). There is no cpufreq-set command in 11.04.

[PGScooter]

I don't know about others, but I am only interested in 12.04. I'm not interested in trying to get rid of the bug in 11.04. So maybe it would be better if I bugged you when 12.04 is released?

Thanks again for your help.

[marshmallow1304]

This bug is still present on my PanP5 running Gentoo with linux-3.2.1. It affects the ondemand cpu governor when resuming from suspend. It does not seem to affect any other governors or hibernation.

Here's how to reproduce:
1) set cpu governor to ondemand
2) start multiple instances of glxgears or similar
- ondemand governor properly adjusts cpu frequency to handle load
3) suspend
4) resume
5) start multiple instances of glxgears or similar
- ondemand governor is stuck at the lowest frequency (800 MHz on my machine)

If I set the frequency manually, it changes. Then if I go back to the ondemand governor, frequency will stay at higher levels as needed. However, once the frequency drops, it will never increase to a higher level. A reboot fixes things.

[isantop]

That's actually excellent information. I'll try and pull out a PanP5 and replicate this bug, then get it filed. It's good to know it's a kernel bug, too. Knowing the source of a problem is sometimes half of getting it fixed.

[PGScooter]

Hey Ian, have you had a chance to look at this?

[HotShotDJ]

This is still going on in Ubuntu? What I can tell you is that it was fixed in OpenSUSE since at least version 11.4 -- my PanP5 happily suspends/resumes without "locking" the CPU with OpenSUSE 12.1.

If the bug is upstream -- that is, with the Kernel -- then perhaps trying a newer kernel from http://kernel.ubuntu.com/~kernel-ppa/mainline/ might help. IIRC, I noticed that the bug had been fixed for me in OpenSUSE starting with the 3.0 kernel... but I might be wrong on that, but it was certainly fixed by 3.1.

Given that Marshmallow is reporting the problem with Gentoo + Kernel 3.2, I suspect that the problem might be with the way that Ubuntu kernel maintainers are compiling the kernel rather than with the kernel itself. But I haven't been tracking Ubuntu development and I don't have a machine to test this hypothesis.

I hope this info helps you track down the problem.