On Fri, 13 Apr 2012, Stephen Warren wrote: > On 04/13/2012 01:46 PM, Alan Stern wrote: > > On Fri, 13 Apr 2012, Stephen Warren wrote: > >> I've tested the patch, and can unplug a USB device, wait 10 seconds, > >> then plug it back in, and everything works as expected. > >> > >> However, I don't notice /sys/devices/.../power/runtime_status ever > >> saying anything other than active, and I can't cat autosuspend_delay_ms, > >> so I assume I'm still not triggering the path you want me to test. I do > >> have PM_RUNTIME turned on. Any ideas? Do I need some patch to the USB > >> core to enable this? I tested on next-20120413 plus a few local patches. > > > > autosuspend_delay_ms isn't relevant here; the controller should be > > suspended with no delay as soon as the root hub suspends. No other > > patches should be needed; it sounds like you're doing everything right. > > > > If you enable CONFIG_PM_ADVANCED_DEBUG along with CONFIG_PM_RUNTIME, > > what do all the other power/runtime_* files show? > > The EHCI controller's active_kids count stays at 1 all the time. I > assume that's the root USB hub device. Looking in its power/ directory, > I see that even when nothing is plugged in, runtime_status==enabled, > even with no active_kids or runtime_usage: That does indeed sound like a bug. > [ 242.611209] usb 3-1: USB disconnect, device number 4 > root@ilyich:/sys/devices/tegra-ehci.2/usb3/power# cat async > enabled > root@ilyich:/sys/devices/tegra-ehci.2/usb3/power# cat autosuspend_delay_ms > 0 Odd... This should contain 2000. Maybe some userspace program has changed it? Either value would be okay, however. You could try writing 2000 to this file, then plugging in a device and unplugging it. The root hub should then suspend 2 seconds after you unplug the device. > root@ilyich:/sys/devices/tegra-ehci.2/usb3/power# cat control > auto > root@ilyich:/sys/devices/tegra-ehci.2/usb3/power# cat runtime_active_kids > 0 > root@ilyich:/sys/devices/tegra-ehci.2/usb3/power# cat runtime_active_time > 262840 > root@ilyich:/sys/devices/tegra-ehci.2/usb3/power# cat runtime_enabled > enabled > root@ilyich:/sys/devices/tegra-ehci.2/usb3/power# cat runtime_status > active > root@ilyich:/sys/devices/tegra-ehci.2/usb3/power# cat > runtime_suspended_time > 0 > root@ilyich:/sys/devices/tegra-ehci.2/usb3/power# cat runtime_usage > 0 > > Are the wakeup_* files in this directory relevant? wakeup says > "disabled", and all the others are empty. No, the wakeup files aren't relevant -- they refer to system sleep, not runtime suspend. Is CONFIG_PM_SLEEP disabled? It should be, since you don't support system suspend. I don't know what's going wrong. Maybe if you enable CONFIG_USB_DEBUG while running your test, something will show up. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
