Re: Suspend/Resume/Hibernation - bisecting or bug-logs?

[Andrey Borzenkov <arvidjaar@mail.ru>]

Kristoffer Ericson wrote:

> Greetings,
> 
> Ive been following your discussion and documentation efforts concerning pm
> in the kernel. This has in the past been a gray area which was hard to
> find information about so kudos.
> 
> I maintain 2 handheld platforms that would benefit greatly from
> implementing proper pm (mainly suspend) but Im having problems bugtracking
> it. Currently the system tries to suspend but fails somewhere and then
> tries to resume (which fails). The end result however is that Im unable to
> see anything (bugmessages...) since the video driver gets deactivated by
> pm.
> 
> My question is this: Is bisecting (turning off device support in kernel
> until it works) the best approach when bugtracking pm suspend? Or is there
> any other logging system that I can use?
> 

Good question. I could use advice too :)

Bisecting is good only if you have known good and known bad versions. From
your description it sounds like it has never worked - so bisecting won't
help. Also sometimes bisecting hits way too large commit (this happened to
me when ACPI replaced mutex with spinlock).