Hi!

So one problem I was having with my new code is that swsusp "hooks" of
enter_state() early and doesn't go through the "normal" callback
mecanism, thus wasn't calling any of my new callbacks.

In addition, it has its own save/restore_processor_state that do not go
through pm_ops, but instead are arch inlines (and besides, I never found
any use of those for saving/restoring processor state, though I do use
them for other means, the semantics are quite crappy here).

Well, i386 definitely uses them for saving some 'less important' cpu
registers.

This is all fairly inconsistent.

What about (note: I'm proposing here to do the job, not asking you to do
it) merging at least disk.c into main.c, that is, having swsusp just use
the "normal" infrastructure ?

Merging disk.c and main.c is certainly good idea, I never know which
one to look in, anyway.

suspend_prepare() and suspend_finish() are pretty much equivalent to
what disk.c does in (un)prepare_processes(), prepare_devices() and
finish() with the exception of free_some_memory() which is not used in
suspend to ram, and swsusp does this totally bogus SMP tricks (they
really can't work properly, you'll deadlock trying to use them,
really !)

Those smp tricks... see my development tree at
www.kernel.org/...git/pavel/work.git. We actually use cpu hotplug
infrastructure and it should work ok.

Then, the "main" implementation does ops->enter(). On swsusp, this enter
sort-of depdends of the "type" of suspend to disk required. Either
"enter" does all the job (PM_DISK_FIRMWARE) which is then totally
equivalent to the core code needs, or it's replaced by a blurb that does
swsusp_suspend, swsusp_write, etc...

PM_DISK_FIRMWARE can be safely removed. See feature-removal*,
DISK_FIRMWARE is S4BIOS.

Finally, the whole pm_disk_mode is just disgustingly ugly. Especially
the fact that the user can go muck around and change it. I do not
support any mode but "PM_DISK_PLATFORM" on ppc and I really think that
should be the only implementation. That is, it's up to the platform
provided pm_ops to decide what to  do. Either doing all the work, or
using swsusp_suspend/swsusp_disk and then restart or shutdown or
whatever. This is all platform specific. Here, basically, the genric
code is exposing some x86 crappola.

PM_DISK_REBOOT is very usefull for testing (and I believe generic; you
could do that on ppc too). PM_DISK_SHUTDOWN is usefull for using
normal powerdown paths in case something is wrong with disk-specific
powerdown. We should move away from it, but please try not to kill it.

								Pavel