[Ubuntu Wiki] Update of "DebuggingKernelSuspend" by penalvch
Ubuntu Wiki
noreply at ubuntu.com
Sun Oct 28 22:37:20 UTC 2012
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The "DebuggingKernelSuspend" page has been changed by penalvch:
http://wiki.ubuntu.com/DebuggingKernelSuspend?action=diff&rev1=36&rev2=37
Comment:
Due to https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1070627 added request for full computer model and BIOS update.
The debugging procedure described below requires a linux kernel with the capability of "/sys/power/pm_trace". You can ensure that pm_trace'ing is possible by looking in the directory /sys/power/ (from a terminal type {{{ls /sys/power/}}})
to see if a file called pm_trace exists.
+ = Debugging information to provide in your bug report =
+
+ 1. Full computer manufacturer and model.
+ 1. If you upgrade your BIOS to the newest version available, does this change anything?
+ 1. Resume trace mentioned below.
+
- = "resume-trace" debugging procedure for finding buggy drivers =
+ == "resume-trace" debugging procedure for finding buggy drivers ==
Resume problems are difficult to debug. The approach used here needs to make notes on progress during resume and be able to recover them after a manual reboot. But there is no non-volatile storage available at the time resume is bringing up your computer. The only hardware on a PC motherboard that retains information across power cycles is the real time clock (RTC), so that is what is used. For those that want to know the details, read Documentation/power/s2ram.txt in your kernel sources. The implementation of suspend/resume debug trace is in drivers/base/power/trace.c.
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