Re: 2.6.29-rc3: tg3 dead after resume

Matt Carlson
2009-01-29T02:20:04Z

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.