On Wed, 26 May 2010, Rafael J. Wysocki wrote: > On Wednesday 26 May 2010, Alan Stern wrote: > > Rafael: > > > > I've been updating the patch Matthew Garrett posted last November, > > adding runtime PM methods for PCI USB controllers. Overall the > > situation is now easier, since the rest of the USB subsystem has been > > converted over to the runtime PM framework. And it even seems to work! > > > > But there is one problem. The device driver needs to know, during its > > pm_suspend callback, whether or not wakeup should be enabled. (Or more > > accurately, the pm_suspend callback needs to fail if wakeup isn't going > > to be available.) > > The driver can check that by calling pci_dev_run_wake() which returns false > if there's no wakeup support for the device. Ah, okay, thanks. > However, that's not enough on > some broken machines where some signal pins are simply not connected to the > system core logic (as a result the PCI core thinks that wakeup is supported, > but in fact it doesn't work due to the broken hardware - yes, there are > machines like this in the wild, Matthew has one). We don't have to worry about that. If the hardware is broken and the kernel doesn't realize it, the user will just have to tell it not to allow runtime suspend for those devices. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
