On Thu, 20 Oct 2016, Lukas Wunner wrote: > On Tue, Oct 11, 2016 at 11:18:28AM -0400, Alan Stern wrote: > > On Sat, 8 Oct 2016, Lukas Wunner wrote: > > > The PCI core already calls pm_runtime_get_sync() before invoking the > > > ->probe hook of a driver (see local_pci_probe()). Drivers need to > > > explicitly release a runtime ref to allow their device to suspend. > > > For xhci-pci, this seems to happen in usb_hcd_pci_probe(): > > > > > > if (pci_dev_run_wake(dev)) > > > pm_runtime_put_noidle(&dev->dev); > > > > > > So you could either modify the if-condition if you want to change the > > > behaviour for XHCI devices only, or if you want to change it in general, > > > add something like this to pci_dev_run_wake(): > > > > > > /* PME capable in principle, but not from the intended sleep state */ > > > if (dev->pme_support && !pci_pme_capable(dev, pci_target_state(dev))) > > > return false; > > > > > > I've briefly looked over the callers of pci_dev_run_wake() and the above > > > seems safe but you should double-check them. > > > > That seems like a good suggestion. The patch is below; Pierre, can you > > test it? This should remove the need to set the USB autosuspend module > > parameter to -1. > > Alan, how do we proceed with this? Are you going to submit a patch > (with commit message, tags and all) to linux-pci@ or would you prefer > me to do that? I just went over the callers of pci_dev_run_wake() > once more and the patch still looks safe to me. Thanks for checking. I intend to submit it soon; there just hasn't been enough free time this week. :-( 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
