Unable to reach C3 or C4 powersaving states when uhci_hcd is in kernel, or radeon driver (r300) is in use.

[GiuseppeVerde]

I recently noticed that my CPU does not enter C3 or C4 powersaving states. It's never done C4, so that's not a big deal, but C3 is important. I've removed the usb drivers not no avail. Then, after Beryl locked up, I had to reboot and checked by logging in to a virtual console. The processor was doing C3 states just fine. I've figured out the following thus far:

1) It only happens when I'm logged in and before anything outside of my session list has run
2) It does not involve Beryl (unless it's the applet; when I logged in, I was running metacity).

Any suggestions on what to poke? I really really really want long battery life!

[GiuseppeVerde (launchpad-digitasaru)]

I have just isolated the problem to the r300 or radeon DRM (found by commenting out the drm module line in xorg.conf, removing the radeon and drm modules from the kernel and starting Xorg) as well as uhci_hcd.

The radeon problem is interesting, because it only blocks C3 or lower states when you're in X. If you swtich to another VC, you will be using C3.

The uhci_hcd issue is somewhat thornier, as I believe that my bluetooth controller might be detected on the USB bus is brought back online. Regardless, whenever uhci_hcd is in the kernel, I don't get C3.

[Brian Murray (brian-murray)]

Thanks for taking the time to report this bug and helping to make Ubuntu better. With which version of Ubuntu did you notice this issue? Thanks in advance.

[GiuseppeVerde (launchpad-digitasaru)]

Feisty, for about a month or so.

I can reliably get C3 (and even C4!) when I:
  1) Remove the dri module loading in xorg.conf
  2) either remove uhci_hcd or disable bluetooth+ipw2100 card by the hardware switch.

Both conditions must be satisfied to get to C3 states and below.

[Brian Murray (brian-murray)]

Thanks for taking the time to report this bug and helping to make Ubuntu better. Unfortunately we can't fix it, because your description doesn't yet have enough information.
Please include the following additional information, if you have not already done so (please pay attention to lspci's additional options), as required by the Ubuntu Kernel Team:
1. Please include the output of the command 'uname -a' in your next response. It should be one, long line of text which includes the exact kernel version you're running, as well as the CPU architecture.
2. Please run the command 'dmesg > dmesg.log' and attach the resulting file 'dmesg.log' to this bug report.
3. Please run the command 'sudo lspci -vvnn > lspci-vvnn.log' and attach the resulting file 'lspci-vvnn.log' to this bug report.
For your reference, the full description of procedures for kernel-related bug reports is available at https://wiki.ubuntu.com/KernelTeamBugPolicies . Thanks in advance!

[GiuseppeVerde (launchpad-digitasaru)]

$ uname -a
Linux petrus 2.6.20-15-generic #2 SMP Sun Apr 15 07:36:31 UTC 2007 i686 GNU/Linux

[CoolkcaH (coolkcah)]

I only get C1 and can't suspend or hibernate.

Linux coolkcah 2.6.20-16-generic #2 SMP Thu Jun 7 19:00:28 UTC 2007 x86_64 GNU/Linux

[Launchpad Janitor (janitor)]

Beginning with the Hardy Heron 8.04 development cycle, all open Ubuntu kernel bugs need to be reported against the "linux" kernel package. We are automatically migrating this bug to the new "linux" package. However, development has already began for the upcoming Intrepid Ibex 8.10 release. It would be helpful if you could test the upcoming release and verify if this is still an issue - http://www.ubuntu.com/testing . If the issue still exists, please update this report by changing the Status of the "linux" task from "Incomplete" to "New". We appreciate your patience and understanding as we make this transition. Thanks!

[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.

[Michele Mangili (mangilimic)]

We are closing this bug report because it lacks the information we need to investigate the problem, as described in the previous comments. Please reopen it if you can give us the missing information, and don't hesitate to submit bug reports in the future. To reopen the bug report you can click on the current status, under the Status column, and change the Status back to "New". Thanks again!