On Monday, January 12, 2015 11:39:18 AM Alan Stern wrote: > On Mon, 12 Jan 2015, Rafael J. Wysocki wrote: > > > On Thursday, January 08, 2015 10:51:06 AM Alan Stern wrote: > > > On Thu, 8 Jan 2015, Rafael J. Wysocki wrote: > > > > > > > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > > > > > > > Commit f25c0ae2b4c4 (ACPI / PM: Avoid resuming devices in ACPI PM > > > > domain during system suspend) modified the ACPI PM domain's system > > > > suspend callbacks to allow devices attached to it to be left in the > > > > runtime-suspended state during system suspend so as to optimize > > > > the suspend process. > > > > > > > > This was based on the general mechanism introduced by commit > > > > aae4518b3124 (PM / sleep: Mechanism to avoid resuming runtime-suspended > > > > devices unnecessarily). > > > > > > > > Extend that approach to PCI devices by modifying the PCI bus type's > > > > ->prepare callback to return 1 for devices that are runtime-suspended > > > > when it is being executed and that are in a suitable power state and > > > > need not be resumed going forward. > > > > > > Does this correctly handle PCI devices that aren't included in the ACPI > > > tables? For example, add-on PCI cards? > > > > Well, it would if it took the case when a device was configured for remote > > wakeup at run time but was not supposed to wakeup the system from sleep into > > account. > > > > That needs to be checked in pci_dev_keep_suspended() rather than in the platform > > callback to cover all devices. > > > > Updated patch follows. > > > > Rafael > > This looks better, thank you. Well, it still has the problem that the current ACPI wakeup setting may not be suitable depending on the PM_QOS_FLAG_REMOTE_WAKEUP value which I overlooked before. I need to restore the check against adev->wakeup.prepare_count in acpi_pci_need_resume() to cover that I think. Will post a v2 with that fixed. -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- 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
