On Tuesday, September 27, 2011, Sarah Sharp wrote: > On Tue, Sep 27, 2011 at 12:20:26AM +0200, Rafael J. Wysocki wrote: > > On Sunday, September 25, 2011, Rafael J. Wysocki wrote: > > > On Thursday, September 22, 2011, Sarah Sharp wrote: > > > > On Mon, Sep 19, 2011 at 11:43:33PM +0200, Rafael J. Wysocki wrote: > > > Without looking at the tables at the moment (I'll do that later), > > > I think that they are missing the information that GPE 0D is a wakeup > > > GPE for the xHCI device. > > > > The DSDT appears to contain that information, so I'm not sure what's > > going on. Perhaps you can put a debug printk into acpi_dev_run_wake() > > to see if that function is called for the xHCI controllers? > > I put a printk in acpi_dev_run_wake(), and that shows up in the original > dmesg I sent: > > Sep 22 10:47:09 talon kernel: [ 2026.211933] xhci_hcd 0000:00:14.0: acpi_pci_run_wake - enable dev wake > Sep 22 10:47:09 talon kernel: [ 2026.211936] acpi device:34: acpi_dev_run_wake - enable dev wake > Sep 22 10:47:09 talon kernel: [ 2026.211955] acpi device:34: acpi_dev_run_wake - return -19 OK, can you printk() dev->wakeup.gpe_number here? [/me realizes that "error" is not really used in this function. Bah.] > The patch I've been using for adding debugging to the PCI and ACPI code > is attached. I've been adding printks willy-nilly to try to understand > what's going on. That's fine. > > > > In digging through the ACPI code, I noticed that acpi_bus_get_flags() > > > > looks for the ACPI methods _PR0 or _PS0 and sets > > > > device->flags.power_manageable to 1 if either of those methods are > > > > successfully invoked. When I deassembled the ACPI tables, I didn't see > > > > either method for any of the USB host controllers in the system. > > > > However, the power_manageable flag only indicates that the device can > > be put into low-power states through ACPI methods, it shouldn't have > > any effect on the wakeup settings. > > Ok, good to know. > > > > > device->flags.power_manageable is checked later when the runtime PM > > > > system attempts to put the PCI device into a lower state, but it seems > > > > to be ignored? Is it supposed to be ignored? > > > > > > Hmm, not really. I'll have a look at that later. > > > > It is used to decide whether or not to call __acpi_bus_set_power(), AFAICS. > > If it is not set, this function is not called, which is OK. Still, > > devices for which it is not set may be put into low-power states and may > > generate wakeup signals. > > > > For many PCI devices there are two possible power management interfaces, > > the native one and the ACPI-based one. All of the modern devices support > > the native power management interface, so they can be put into low-power > > states even if the ACPI-based interface is missing for them (which is the > > case for your USB controllers). For those devices, if the ACPI-based > > interface is not present, we simply use the native one only. > > So if I understand you correctly, the kernel can use the native PCI power > management interface to put the PCI device into a lower power state... > > > As far as wakeup is concerned, we should enable them to generate PME > > using the native interface and in addition to it we should use ACPI to > > enable the wakeup GPEs that are supposed to be triggered in response to > > the PME signals. > > ...but the kernel ACPI core will still be watching for the SCI that the > firmware generates on a PME wakeup? Correct? Yes, it should work like this. > Is the native PCI power management interface you're referring to > implemented through the PCIe PME driver? No, this is what pci_raw_set_power_state() does. > Because this particular host controller is a PCIe device, not a PCI device. Well, PCIe is PCI to some extent. :-) > I added some debug statements to drivers/pci/pcie/pme.c, but the dmesg shows > that none of them got called. This one only handles the native PME signaling, which is a PCIe feature (instead of using ACPI GPEs for that, it signals PME via interrupts from Root Ports). Of course, it only works if you have those "PCIe PME" entries in /proc/interrupts. > > This apparently doesn't work correctly on your system and we need to figure > > out why. > > Ok. Do you have suggestions for any tests I can run or debugging > statements to add? I'm really not an ACPI expert and I've been > basically fumbling in the dark. Yes, please see above. I need to know the number of the GPE it tries to enable for the USB controller. Thanks, Rafael -- 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
