Re: -mm swsusp: do not default to platform/firmware

[Pavel Machek <pavel@suse.cz>]

Hi!

> > -mm swsusp now defaults to platform/firmware suspend... That's
> > certainly unexpected, changes behaviour from previous version, and
> > only works on one of three machines I have here. I'd like the default
> > to be changed back.
> 
> You overestimate my knowledge of suspend stuff.  AFAICT the current -mm
> default is to enter ACPI sleep state via the BIOS rather than via Linux's
> ACPI driver.  Correct?

Its actually bit more complex. There are 3 methods:

shutdown: save state in linux, then tell bios to powerdown

platform: save state in linux, then tell bios to powerdown and blink
	  "suspended led"

firmware: tell bios to save state itself

"platform" is actually right thing to do, but "shutdown" is most
reliable.

Old code always did "shutdown". New code does "shutdown", "platform"
or "firmware" depending on what BIOS can do.

> If not, then what?
> 
> If so, then why do we feel this change is needed, and why did Pat change things?
> 
> My major concern here is that Pat may have made that change to get suitable
> coverage testing for new code paths, and we wouldn't want to undo that right away.

I believe "platform" is so unreliable (for now) that it blocks usefull
testing... I'd like it to default to "shutdown" when it is merged
upstream.
									Pavel
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