XO-1.75/Kernel/Issues

hang, mmp2-pcm-audio.0 resume

This is a hang with the last serial console message:

mmp2-pcm-audio mmp2-pcm-audio.0: resume

No FIQ. No SysRq. Always preceeded by a PM: Some devices failed to suspend.

Jon Nettleton says known problem. Caused by interrupted suspend, and during the unwind of the resume it hangs.

Can be worked around by removing the audio driver from the kernel.

Disabling runin-sound has no effect.

Seen within half an hour if SUS_TIME is set to 3000. Rarely or never seen if SUS_TIME is set to 10000.

Theory: once a suspend takes too long, the RTC alarm goes off before suspend has finished, and the suspend is interrupted, leading to this issue.

Impact: may trigger also with other wake sources, leading to a failed runin.

Instances:

• http://dev.laptop.org/~quozl/z/1RiDms.txt
• http://dev.laptop.org/~quozl/z/1RiEIr.txt

Might be fixed by http://dev.laptop.org/git/olpc-kernel/commit/?h=arm-3.0-wip-wfi&id=92ef8264199818b91518f7fe7af365c5998381fa

hang, mmp2_pm_finish: Enable audio island

This is a hang shortly after the serial console message:

mmp2_pm_finish: Enable audio island

The time period may vary.

Only occurs with SUS_TIME not set to 3000.

Tracing the point of hang by gradually adding printk has shown the problem occurs in dpm_resume(), before dpm_complete() is called by dpm_resume_end().

Instances:

• http://dev.laptop.org/~quozl/z/1RiHT6.txt (75.904ms)
• http://dev.laptop.org/~greenfeld/temp/175bringup/os23-ff199462/screenlog.3-resumehang2ecmod.bz2 (80.341ms)
• http://dev.laptop.org/~greenfeld/temp/175bringup/os23-26f404e/screenlog.6-resumehang.bz2 (2.683ms)
• http://dev.laptop.org/~greenfeld/temp/175bringup/os23-26f404e/screenlog.3-ecfail1.bz2 (72.616ms)
• http://dev.laptop.org/~quozl/z/1Rhvmt.txt
• http://dev.laptop.org/~quozl/z/1RhvpV.txt
• http://dev.laptop.org/~quozl/z/1RiK9g.txt (proving it does not require the body of the function)