On Mon, 13 Aug 2018, Anshuman Gupta wrote: > On Mon, Aug 13, 2018 at 01:19:26PM +0530, Oliver Neukum wrote: > > On Mo, 2018-08-13 at 12:15 +0530, Anshuman Gupta wrote: > > > Hi , > > > I need to test a functionality with USB autosuspend with latest kernel > > > Linux 4.18-rc8. I am trying to autosuspend a USB key board, i enabled > > > its autosuspend by doing echo "auto" to its "control" attributes. > > > I am expecting USB keyboard to go to autosuspend after autosuspend_delay_ms. > > > But USB key board is not going to autosuspend because its runtime usage > > > count is not equal to zero. > > > > > > Below are the log snippets: > > > > > > root@intel-Kabylake-Client-platform:# cat /sys/bus/usb/devices/1-5/power/runtime_enabled > > > enabled > > > root@intel-Kabylake-Client-platform:# cat /sys/bus/usb/devices/1-5/power/control > > > auto > > > root@intel-Kabylake-Client-platform:# cat /sys/bus/usb/devices/1-5/power/autosuspend_delay_ms > > > 2000 > > > root@intel-Kabylake-Client-platform:# cat /sys/bus/usb/devices/1-5/power/runtime_status > > > active > > > root@intel-Kabylake-Client-platform:# cat /sys/bus/usb/devices/1-5/power/runtime_usage > > > 1 > > > root@intel-Kabylake-Client-platform:# sleep 60; cat /sys/bus/usb/devices/1-5/power/runtime_usage > > > 1 > > > > > > My USB keyboard runtime usage reference count is not decreasing to zero. > > > Here am i missing something regarding runtime usage count or is it some issue with > > > my kernel or OS? > > > > Very hard to say without further information. Is the HID device the > > only interface of the whole device? > yes, HID device is only the interface for given device, below here lsusb -t log for usb dev 1-5. > > root@intel-Kabylake-Client-platform:# lsusb -t > /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/12p, 480M > |__ Port 5: Dev 3, If 1, Class=Human Interface Device, Driver=usbhid, 1.5M > |__ Port 5: Dev 3, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M > > > Does the device support remote wakeup? > yes, from lsusb logs it seems, it is supporting remote wakeup. > > root@intel-Kabylake-Client-platform:# lsusb > Bus 001 Device 003: ID 04d9:1702 Holtek Semiconductor, Inc. Keyboard LKS02 > > root@intel-Kabylake-Client-platform:# lsusb -v -d 04d9:1702 | grep Remote > Remote Wakeup > > > Is an LED on? > Num lock led was on, but switching it off also does not help. > > > > Usbhid does support autosuspend, but its criteria must be met. > > And all interface drivers must call the device idle. > All of its interfaces are in runtime suspend > > root@intel-Kabylake-Client-platform:# cat /sys/bus/usb/devices/1-5\:1.0/power/runtime_status > suspended > root@intel-Kabylake-Client-platform:# cat /sys/bus/usb/devices/1-5\:1.1/power/runtime_status > suspended > root@intel-Kabylake-Client-platform:# cat /sys/bus/usb/devices/1-5/power/runtime_active_kids > 0 What matters is not the power/* settings for the interfaces themselves, but rather the power/* settings for the interfaces' children. Alan Stern
