Kernel Bug Tracker – Bug 3916
CONFIG_USB_SUSPEND=y breaks APM Suspend to RAM
Last modified: 2006-04-11 03:44:45 UTC
Distribution: Fedora Core 3
Hardware Environment: IBM Thinkpad R40
Software Environment: kernel 2.6.9 and up (tested 2.6.10-rc3 and 2.6.10-rc3-bk12)
Problem Description: My r40 is running under APM. Suspend to RAM via Fn+F4
always worked for me, until Fedora started shipping 2.6.9 kernels. Since then
the notebook powers down ok and the LED indicating that it's sleeping is on, but
after some (~3) minutes, it wakes up on its own and hangs forcing a hard reset.
After some fiddling with different kernels and different configs, I found out
that this faulty behaviour is triggered by the kernel setting
CONFIG_USB_SUSPEND=y. If this option isn't set, the problem doesn't occur, as
soon as it is set the problem is there. Tested with 2.6.9 from Fedora Core 3,
and plain 2.6.9, 2.6.10-rc3 and 2.6.10-rc3-bk12 from kernel.org.
Steps to reproduce:
1. Build a kernel with CONFIG_USB_SUSPEND=y
2. Boot it with kernel arguments acpi=off apm=on
3. Initiate APM Suspend to RAM (on a thinkpad by hitting Fn+F4)
4. See it go to sleep alright
5. Wait some minutes
6. See that it wakes up without you doing anythink
7. See that it hangs forcing you to do a hard reset
Created attachment 4282 [details]
Kernel config for 2.6.10-rc3-bk12 triggering the bug
Fedora's bug was enabling that particular EXPERIMENTAL feature.
On a different topic, 2.6.15 USB should handle suspend transitions
a lot better.
What is the status of this issue in kernel 188.8.131.52?
It seems the issue is resolved in 184.108.40.206, at least I can't reproduce the error
any more. I'll close the bug for now but do some more tests in the weekend and
re-open if needed.