On Friday, April 12, 2013 10:12:32 PM Benenati, Chris J wrote:
> >On Thursday, April 11, 2013 11:13:49 PM Benenati, Chris J wrote:
> >> In 3.2, the marked lines (***) below were added:
> >>
> >> static int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state)
> >> {
> >> int error;
> >>
> >> if (platform_pci_power_manageable(dev)) {
> >> error = platform_pci_set_power_state(dev, state);
> >> if (!error)
> >> pci_update_current_state(dev, state);
> >> *** /* Fall back to PCI_D0 if native PM is not supported */
> >> *** if (!dev->pm_cap)
> >> *** dev->current_state = PCI_D0;
> >> } else {
> >> error = -ENODEV;
> >> /* Fall back to PCI_D0 if native PM is not supported */
> >> if (!dev->pm_cap)
> >> dev->current_state = PCI_D0;
> >> }
> >>
> >> return error;
> >> }
> >>
> >> If the target state is PCI_D3, the new code serves to *undo* the marked code below executed by the preceding call to pci_update_current_state() when PCI PM registers are not present:
> >>
> >> void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
> >> {
> >> if (dev->pm_cap) {
> >> u16 pmcsr;
> >>
> >> pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
> >> dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
> >> } else {
> >> *** dev->current_state = state;
> >> }
> >> }
> >>
> >> This is despite the fact that platform_pci_power_manageable() indicated that the platform FW could handle it and the succeeding call to platform_pci_set_power_state() succeeded. That means that devices with FW support but no PCI PM support will be left in the wrong state.
> >>
> >> It appears the new "if" statement should be "else if":
> >>
> >> if (!error)
> >> pci_update_current_state(dev, state);
> >> *** else if (!dev->pm_cap) /* Fall back to PCI_D0 if native PM is not supported */
> >> *** dev->current_state = PCI_D0;
> >>
> >> Rafael concurs with me.
> >
> >Yes, I do.
> >
> >Are you willing to submit a patch fixing the problem (essentially the change you've proposed above), or do you want me to do that?
> >
> >Rafael
>
> I have never submitted a patch and do not know the procedure, so would appreciate it if you would do it. Thanks.
No problem, posted a while ago.
Thanks,
Rafael
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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