Re: 2.6.29-rc3: tg3 dead after resume

Rafael J. Wysocki
2009-01-29T22:22:26Z

On Thursday 29 January 2009, Matt Carlson wrote:
> On Wed, Jan 28, 2009 at 06:10:37PM -0800, Linus Torvalds wrote:
> >
> >
> > On Wed, 28 Jan 2009, Parag Warudkar wrote:
> > >
> > > Sure, diff -u below. There are differences but not sure if they are
> > > abnormal or expected.
> >
> > Well, they're all in the "extended set", ie not the basic registers that
> > the PCI layer saves. The PCI layer normally just saves the low 16 dwords,
> > along with the PCI[EX] capability thing.
> >
> > None of the PCI save/restore routines have ever saved the extended state
> > (well, "ever" is a strong word - I think we long ago used to pass in how
> > many bytes we wanted saved, but got rid of it), and it certainly didn't
> > change with the recent PCI suspend/resume changes.
> >
> > I get the feeling that it's some odd tg3 issue. That tg3 driver does have
> > that special
> >
> > /* Make sure register accesses (indirect or otherwise)
> > * will function correctly.
> > */
> > pci_write_config_dword(tp->pdev,
> > TG3PCI_MISC_HOST_CTRL,
> > tp->misc_host_ctrl);
> >
> > in its own version of setting the power state, and maybe that really
> > _must_ happen before we actually set the state back to PCI_D0. That sounds
> > very odd, but hey..
> >
> > I added Matt Carlson to the cc, since he seems to be the main tg3
> > authority here.
> >
> > Matt: the whole discussion is on netdev and the kernel mailing list, but
> > the short version is that -rc3 suspends and resumes for Parag again
> > (unlike -rc2), but tg3 doesn't appear to resume properly. The generic PCI
> > layer now does more at resume time (very early, when interrupts are still
> > off), see
> >
> > - pci_pm_resume_noirq ->
> > pci_pm_default_resume_noirq() ->
> > pci_restore_standard_config()
> >
> > for more of the details (basically it always does that
> > "pci_restore_state()" and tries to bring the device back to PCI_D0).
>
> Thanks Linus. I'm looking over the diffs Parag sent and I already see
> some suspicious register settings. Let me think about this some more
> and then I'll jump into the discussion.

FWIW, I can't reproduce the problem with tg3 on my testbox. Suspend to RAM
and resume seem to work correctly on it.

Thanks,
Rafael