Re: [linux-pm] [3/6] 2.6.21-rc4: known regressions

Maxim
2007-03-28T22:26:18Z

On Wednesday 28 March 2007 22:42:00 Linus Torvalds wrote:
>
> On Wed, 28 Mar 2007, David Brownell wrote:
> >
> > On Wednesday 28 March 2007 9:38 am, Linus Torvalds wrote:
> >
> > > It's a *device*, dammit. It should save and resume like one (probably as a
> > > system device). The "set_mode()" etc stuff is at a completely different
> > > (higher) conceptual level.
> >
> > Agreed, except about "probably as a system device".
> >
> > Last I checked, there was no good reason to use sysdev suspend()/resume()
> > rather than platform_device suspend_late()/early_resume(). Which more
> > or less means no good reason to use sysdev in new code...
>
> I won't disagree - it might well be much nicer to just show it in the
> "real" device tree. I'm not 100% sure where in the tree it would go,
> though. It should probably be "inside" the root entry, before any of the
> PCI buses. It's generally what we've used those "system device" things
> for, but I agree that it would be better to just make system devices show
> up early on the regular device list than it is to have them be special
> cases.
>
> Bit I think that's a separate (and fairly small) issue compared to the
> "don't use the clocksource infrastructure as a make-believe suspend/resume
> mechanism" problem that Maxim's patch had.
>
> (Maxim, don't take that the wrong way - I think your analysis and patch
> were great, I just think another organization would be better)

Exactly, I agree completely
I said that my patch was a temporary fix, and I agree that the best way is to create a new system device
and use its suspend/resume hooks to bring HPET back to life on resume.

>
> > Also, making HPET use the legacy mode seems like a step backwards.
>
> I don't think that's actually "legacy" in any sense but the interrupt
> delivery, where the "legacy mode" bit is not so much that the HPET itself
> is "legacy" but that it *replaces* legacy devices.
>
> But I may have misunderstood the thing. I'm an old fart, so I know the old
> timers much better than I know the new ones ;). Somebody feel free to hit
> me with the clue-2x4.
>
> Linus
>

Best regards,
Maxim Levitsky