[linux-pm] [PATCH -mm] kexec jump -v9
Rafael J. Wysocki
rjw at sisk.pl
Thu Mar 20 18:45:23 EDT 2008
On Thursday, 20 of March 2008, Pavel Machek wrote:
> On Tue 2008-03-18 21:25:27, Eric W. Biederman wrote:
> > Alan Stern <stern at rowland.harvard.edu> writes:
> > > On Wed, 19 Mar 2008, Rafael J. Wysocki wrote:
> > >
> > >> Well, I've been saying that for I-don't-remember-how-long: on my box, if you
> > >> use S5 instead of entering S4, the fan doesn't work correctly after the
> > >> resume. Plain and simple.
> > >>
> > >> Perhaps there's a problem with our ACPI drivers that causes this to happen,
> > >> but I have no idea what that can be at the moment.
> > >
> > > IMO it would be worthwhile to track this down. It's a clear indication
> > > that something is wrong somewhere.
> > >
> > > Could it be connected with the way the boot kernel hands control over
> > > to the image kernel? Presumably ACPI isn't prepared to deal with that
> > > sort of thing during a boot from S5. It would have to be fooled into
> > > thinking the two kernels were one and the same.
> > It should be easy to test if it is a hand over problem, by turning off
> > the laptop by placing it in S5 (shutdown -h now) and then booting same
> > kernel again.
> Feel free to help with testing.
> I believe ACPI is simply getting confused by us overwriting memory
> with that from old image. I don't see how you can emulate it with
Well, in fact ACPI has something called the NVS memory, which we're supposed
to restore during the resume and which we're not doing. The problem may be
related to this.
I have fixing that on my todo list, but frankly there's many different things
in there. :-)
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