Re: suspending to disk on FC6 not working

Rafael J. Wysocki
2006-10-01T12:28:19Z

On Sunday, 1 October 2006 07:22, Dave Jones wrote:
> On Sat, Sep 30, 2006 at 10:07:16PM -0700, Pallipadi, Venkatesh wrote:
>
> > >I had not noticed it was not loaded. This maybe a bigger problem. With
> > >the latest FC6 kernel this module gets loaded and thus suspend fails. I
> > >rebuilt the same kernel but plopped this patch in. The module does not
> > >want to load:
> > >
> > ># /sbin/modprobe acpi-cpufreq
> > >FATAL: Error inserting acpi_cpufreq
> > >(/lib/modules/2.6.18-1.2708.cpufreq/kernel/arch/i386/kernel/cpu
> > >/cpufreq/acpi-cpufreq.ko): No such device
> > >
> > >This is why suspend works. But now this module won't load.
> > >
> >
> > The module was not working on your laptop even when suspend was failing.
> > That is what the absence of /sys.../cpufreq says. If this module was
> > working for you earlier and stopped working recently or even otherwise
> > both this and speedstep-centrino does not work on your platform, that is
> > a separate issue. Was this module working and cpufreq supported on your
> > system with any earlier kernels?
>
> One problem acpi-cpufreq faces when built modular compared to the
> other cpufreq drivers is that there's no way of knowing before modprobe'ing
> whether or not it's going to do anything or not, so userspace never knows
> if it's really 'safe' to load this module.
>
> In Fedora, we modprobe the acpi-cpufreq module if all other scaling
> drivers have failed their init routines. Ie, it's treated as a fallback
> "Well, nothing else worked, lets try this, and if this don't work out, bail..."
> When we added this userspace 'fallback', we started getting a bunch of
> reports like the above, from users who had CPUs that couldn't do any scaling
> at all. The STICKY tag was added to the driver so that it would stop
> making noise for those users.
>
> Looking at the problem differently, we *could* add back the sticky tag,
> and add some explicit checks for !data in the suspend/resume paths
> to abort cleanly. It's a bit of a hack though.
>
> hmm?

Well, IMHO, making the module load when we know it won't work is a hack
in the first place. :-)

If you want the sticky tag, the suspend/resume thing should be added too.

Greetings,
Rafael

--
You never change things by fighting the existing reality.
R. Buckminster Fuller