suspend-to-ram high power upon resume + ehci_hcd

[Dave Rosky]

Binary package hint: linux-image-2.6.15-27-686

This bug applies to dapper, I haven't tested edgy.

On this laptop (Dell Inspiron 9400), suspend to ram and resume appears to work, but I noticed that the idle power is much higher upon resume than before suspending (around 25% higher). Note, the cpu usage is normal upon resume (~100% idle), and the C states look normal.

I tried many things, but finally traced the problem down to the USB system, in particular ehci_hcd. I tried removing all USB modules before suspending, and when I resumed, the power was normal. I then started re-inserting the USB modules. I first re-inserted uhci_hcd and the power stayed normal (and the USB mouse got detected). I then re-inserted ehci_hcd and the abnormally high power returned.

I don't know if this is a problem with hardware or with the driver. Is there a way of resetting the USB controller hardware after a resume? If there is, I can try that.

Dave

[Dave Rosky (d-rosky)]

An additional observation:

On the same laptop (Inspiron 9400), SuSE 10.1 can suspend-to-ram and resume without the abnormally high power upon resume.

Dave

[Dave Rosky (d-rosky)]

Changed package to acpi-support since most suspend problems seem to be assigned to that category.

[Matthew Garrett (mjg59)]

No, kernel bugs should be assigned to the kernel.

[Dave Rosky (d-rosky)]

OK, thanks, I wasn't sure.

[Sebastian Rode (sebastian-ro-deactivatedaccount)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. You reported this bug a while ago and there hasn't been any activity in it recently. We were wondering is this still an issue for you? Can you try with latest Ubuntu release? Thanks in advance.

[Sebastian Rode (sebastian-ro-deactivatedaccount)]

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!