lkml.org 
[lkml]   [2012]   [Mar]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [Replacement][PATCH 2/6] PM / Domains: Fix hibernation restore of devices, v2
On Thu, Mar 15, 2012 at 10:00:09PM +0100, Rafael J. Wysocki wrote:
> On Thursday, March 15, 2012, Simon Horman wrote:
> > On Tue, Mar 13, 2012 at 10:32:42PM +0100, Rafael J. Wysocki wrote:
> > > On Tuesday, March 13, 2012, Rafael J. Wysocki wrote:
> > > > From: Rafael J. Wysocki <rjw@sisk.pl>
> > > >
> > > > During resume from hibernation pm_genpd_restore_noirq() has to
> > > > deal with software state left by pm_genpd_suspend_noirq() and
> > > > unknown hardware state (the boot kernel may leave all PM domains and
> > > > devices in arbitrary states). For this reason, make it attempt to
> > > > power cycle each domain when before resuming its first device to
> > > > possibly get rid of any unwanted hardware state that may interfere
> > > > with genpd_start_dev() later on.
> > > >
> > > > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> > >
> > > I realized that this wasn't a good idea because of patch [3/6] (we
> > > can't power cycle domains containing "always on" devices), so I
> > > decided to only fix the really broken things in pm_genpd_restore_noirq().
> > >
> > > Of course, patch [3/6] also needs to be updated on top of the below to
> > > avoid starting "always on" devices in pm_genpd_restore_noirq() (it has
> > > to assume that they will be "always on" in the boot kernel too, but that
> > > seems to be a reasonable expectation).
> > >
> > > Please note that those changes only affect resume from hibernation, so
> > > they don't invalidate the testing that has already been carried out.
> >
> > Hi Rafael,
> >
> > sorry for such a naeive question, but if I was to test
> > hibernate on the Mackerel how would I achieve resume?
> > Is there a button I should press?
>
> Hibernation is not supported on Mackerel at the moment, so you'd need to add
> some platform hooks first. Then, you'd need some persistent storage with
> a swap patrition (or swap file at least) to save the image. You'd need
> to point your kernel to the image storage using the resume= and resume_offset=
> command line switches. Then, you should be able to create an image and the
> kernel would look for it automatically on the next boot.
>
> Still, I'm not sure if doing all that at this point is worth the effort.

Point taken.


\
 
 \ /
  Last update: 2012-03-16 01:05    [W:0.036 / U:1.092 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site