KernelLucidSuspendResumeImprovements

Revision 1 as of 2009-11-19 21:32:46

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Summary

Release Note

Rationale

Userland control of suspend/resume/hibernate

pm-utils.

Diagnosing and Fixing suspend/resume/hiberate

Diagnosing and hence fixing broken suspend/resume/hibernate needs to easier. A Community based Wiki tutorial or troubleshooting guide (such as http://people.freedesktop.org/~hughsient/quirk/quirk-suspend-debug.html) needs to be written as the de-facto reference page to help users to:

  • identify known hardware issues
  • step-by-step diagnose problems
  • gather hardware and kernel specific information that can help pin-point and fix problems

Also having a program/script that can test for known quirks and suggest pm-suspend workarounds would be helpful.

Debugging suspend/resume/hibernate issues can be notoriously difficult; being able do dump kernel messages early to a serial console is useful. However modern PCs do not have legacy serial port hardware, so providing a USB serial console driver in initramfs is required.

Use Cases

  • A user cannot get their laptop to resume. They visit the trouble shooting guide which lists known hardware issues and pm-suspend workarounds that they can try.
  • A user cannot get their laptop to resume. The Wiki trouble shooting guide explains how to run a quirk checking program which can automatically suggest pm-suspend workarounds.
  • A user cannot resume their laptop because they have problems with specific buggy drivers. The Wiki tutorial explains how to turn on the/sys/power/pm_trace "resume-trace" debugging procedure for finding buggy drivers to gather sufficient information to pin-point the relevant broken driver. They can then submit a bug report against this driver.
  • A user cannot hibernate their laptop. The tutorial explains how to make the hibernation core run in a test mode and then run through the 5 different test modes: freezer, devices, platform, processors or core.
  • A user wants to attach an early kernel log message to a bug report. By plugging in a USB-serial dongle and enabling the USB serial console driver they can then capture the log on another PC using hardware which does no have a legacy serial port. The tutorial should explain how to enable the driver using kernel boot line options and how to capture the dmesg log on a 2nd PC over serial using tools such as minicom.
  • A user shuts the laptop lid and put it directly in a bag, possibly a tight fitting neoprene bag. The laptop may take 20 seconds or so to complete the suspend process, but it must always complete to avoid a flat battery and potential fire hazard.

Assumptions

Design

Implementation

pm-utils Quirk Checking Scripts

The Quirk checking script http://people.freedesktop.org/~hughsient/quirk/quirk-checker.sh perhaps could be included into the disto to help users pin-point suspend/resume quirks.

Test/Demo Plan

Unresolved issues

  • OEM Team
    • What does the OEM Team need from the Kernel/Userspace?
    • What are typical and acceptable cycles? i.e. Suspend/Resume 500 times without failure
    • Other?

BoF agenda and discussion

Userland control of suspend/resume/hibernate

  • pm-utils vs DeviceKit-power - risk/benefit of choice

Diagnosing and Fixing suspend/resume/hiberate

References

CategorySpec