Messages in this thread | | | From | (Eric W. Biederman) | Subject | Re: SATA resume slowness, e1000 MSI warning | Date | Fri, 09 Mar 2007 20:41:14 -0700 |
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"Kok, Auke" <auke-jan.h.kok@intel.com> writes:
> Eric W. Biederman wrote: > > [CHOP] > >> Below is an additional set of warnings that should help debug this. >> The old code just got lucky that it triggered a warning when this happens. > > > I'm trying this patch together with the other 2 that you sent out a few days > ago. I'm seeing some minor issues with this and lots of bogus warnings as far as > I can see. > > If I suspend/resume and unload e1000, then reinsert e1000.ko, I immediately hit > the WARN_ON at `msi.c:516: WARN_ON(!hlist_empty(&dev->saved_cap_space));` > > I'm not sure that's useful debugging information. even though saved state exists > the module has been removed, so you might want to purge the state table when the > driver gets removed? > > > anyway, back to testing.
Sorry I should have been clear.
With the last two patches I sent out: pci: Repair pci_save/restore_state so we can restore one save many times. msi: Safer state caching.
Those WARN_ON's are now totally bogus.
In essence the WARN_ON's were testing to ensure pci_save_state and pci_restore_state were paired.
The assumptions was that pci_restore_state would remove everything from the list that pci_save_state placed on it.
When I reworked the code and removed the bogus pairing requirement it meant that if we ever save state and have a pci-e or pci-x capability we will have a state structure on the list until the kernel reboots.
In summary: pci_save_state and pci_restore_state were making a wrong assumption about the world. The WARN_ON patch tested to ensure the world matched those functions. When I fixed those functions to match the world the WARN_ON's became completely bogus.
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