Re: First cut of catch up patch... Still frozen on restore...

Hi.

On 03/01/12 13:25, Woody Suwalski wrote:
> No I have not. For the last 2 years I have been building kernels with
> AGP and video built-in.
> OTOH your suspicion is probably correct, TOI  seems to work fine on
> EeePC with GMA500 video.
> However starting in single mode with no kernel mode setting should be as
> safe as conceptually possible - and kernel itself loads fine - I can see
> that since I am starting TOI from the ramdisk.
> So sooner or later it will need to be debugged - just I do not know how
> to do it?
> 
> There is no real serial on the boxes, but maybe ttyUSB will do? I will
> try to create a smarter ramdisk  and channel dmesg to ttyUSB... Just
> need to find another machine with a real serial port to receive the data
> ;-)
> 
> Any hints w hat to look for? Which parts of TOI/kernel sprinkle with more
> printk's? Any suggestions how to slow it down / flush messages / force
> some maximum-comatibilty mode? Maybe it is some weird timing problem?

I wouldn't bother with sprinkling printks, at least not to begin with.

What I would suggest would be to start with booting to init S or
(better) init=/bin/bash and in the later case, mount /sys, /dev and so
on. Having done that, try hibernating via:

echo 1 > /sys/power/tuxonice/reboot
echo 1 > /sys/power/tuxonice/do_hibernate

If that works, test it a second time. Some bugs in drivers'
suspend/resume routines are such that things seem to work okay the first
time, but die properly on the second attempt.

When you're convinced the current configuration works reliably, add a
kernel module or service one by one, and retry.

If you find the first attempt doesn't work, look at what's built in to
the kernel at the moment and see if you can modularise any of it.

You could also try using a serial console and the verbose PM debugging
compile time option. Another option might be to check out the so-called
'Magic number' (if I recall the terminology used correctly) that's
stored in the clock when the Power Management Debug support is enabled.
It creates a line in your dmesg at start up that says something like
"Magic Number", and the values it gives can be used to find the last
driver suspend/resume call that was made.

Regards,

Nigel
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