Re: Cleanup PCI power states

Pavel Machek
2004-12-17T00:35:25Z

Hi!

> > > Care to resend this, I seem to have lost them :(
> >
> > Could this go to "after 2.6.10 tree", too? It is a helper that
> > converts system state into PCI state. We really do not want to have
> > this copied into every driver, because it will need to change when
> > system state gets type-checked / expanded to struct.
>
> So this is how you want to switch stuff over? Can you give me an
> example of how this will be used?

Yes. Some way to convert between system-state and pci-state is needed;
for now it only silences warning, but I guess it will get more complex
in future.

Example is here:

--- clean/drivers/net/e100.c 2004-10-01 00:30:15.000000000 +0200
+++ linux/drivers/net/e100.c 2004-11-14 23:36:46.000000000 +0100
@@ -2313,7 +2313,7 @@
pci_save_state(pdev, nic->pm_state);
pci_enable_wake(pdev, state, nic->flags & (wol_magic | e100_asf(nic)));
pci_disable_device(pdev);
- pci_set_power_state(pdev, state);
+ pci_set_power_state(pdev, pci_choose_state(pdev, state));

return 0;
}
@@ -2323,7 +2323,7 @@
struct net_device *netdev = pci_get_drvdata(pdev);
struct nic *nic = netdev_priv(netdev);

- pci_set_power_state(pdev, 0);
+ pci_set_power_state(pdev, PCI_D0);
pci_restore_state(pdev, nic->pm_state);
e100_hw_init(nic);

> > --- clean/drivers/pci/pci.c 2004-10-01 00:30:16.000000000 +0200
> > +++ linux/drivers/pci/pci.c 2004-11-14 23:36:46.000000000 +0100
> > @@ -300,6 +300,30 @@
> > }
> >
> > /**
> > + * pci_choose_state - Choose the power state of a PCI device
> > + * @dev: PCI device to be suspended
> > + * @state: target sleep state for the whole system
> > + *
> > + * Returns PCI power state suitable for given device and given system
> > + * message.
> > + */
> > +
> > +pci_power_t pci_choose_state(struct pci_dev *dev, u32 state)
> > +{
> > + if (!pci_find_capability(dev, PCI_CAP_ID_PM))
> > + return PCI_D0;
> > +
> > + switch (state) {
> > + case 0: return PCI_D0;
> > + case 2: return PCI_D2;
> > + case 3: return PCI_D3hot;
> > + default: BUG();
> > + }
> > +}
> > +
> > +EXPORT_SYMBOL(pci_choose_state);
>
> EXPORT_SYMBOL_GPL() perhaps?

Ugh, I do not have any strong feelings here, but I want nvidia etc to
use this one so that they implement driver model properly.

Pavel
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