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SubjectRe: BUG: scheduling while atomic: ip/23212/0x00000102
Date
On Monday, August 04, 2008 3:10 pm Rafael J. Wysocki wrote:
> > - pci_read_config_word(tp->pdev,
> > - pm + PCI_PM_CTRL,
> > - &power_control);
> > - power_control |= PCI_PM_CTRL_PME_STATUS;
> > - power_control &= ~(PCI_PM_CTRL_STATE_MASK);
> > switch (state) {
> > case PCI_D0:
> > - power_control |= 0;
> > - pci_write_config_word(tp->pdev,
> > - pm + PCI_PM_CTRL,
> > - power_control);
> > - udelay(100); /* Delay after power state change */
> > + pci_enable_wake(tp->pdev, state, false);
> > + pci_set_power_state(tp->pdev, PCI_D0);
>
> Still, I don't think drivers should access the standard PCI PM registers
> directly, so perhaps there should be a version of pci_set_power_state()
> using udelay() instead of msleep() or we can just replace the msleep()
> in pci_set_power_state() with udelay()?

I think we should get rid of the open coded PCI PM state management, since
otherwise platform related bugs like the Intel PCIe PM quirk that sets
pci_pm_d3_delay to 120ms would have to be duplicated around the tree.

That said, waiting for 120ms with a busy wait seems a bit absurd if we can
avoid it. Either we need to find a way to make drivers only change states
(which can be very slow) in non-atomic context or we'll need to add a busy
wait variant of the power state call...

Jesse


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