hi alan: 2015-01-06 23:54 GMT+08:00 Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>: > On Tue, 6 Jan 2015, vichy wrote: > >> >> But I cannot see the keyboard go to suspend even I force autosuspend as 0. >> >> is there any other way to trigger runtime suspend immediately instead >> >> of waiting kernel judge it is idle for a while? >> > >> > There may be other reasons why the keyboard does not get suspended. >> > For example, it may not support remote wakeup. What does "lsusb -v" >> > show? And what does usbmon show? >> here is the output of lsusb and usbmon will be attach soon. >> BTW, >> 1. is there any other method to trigger runtime suspend instead of >> waiting device to be idle. >> such as echo xxx > xxxx, and it will directly call runtime >> suspend related function > > No, there isn't. > >> 2. why remote wake up feature of hid is related to runtime suspend? >> runtime suspend is kernel use to saving power and suspend/resume >> actively, right? > > That's true. But it wouldn't work very well if the keyboard went into > runtime suspend and stayed that way even when you tried to type on it! > If a keyboard doesn't support remote wakeup then we must not put it > into runtime suspend. I attach usbmon for your reference. But keyboard is still not working on runtime suspend. > > However, I see from the lsusb output that your keyboard _does_ support > remote wakeup, so that isn't the reason. > >> 3. for host part, runtime suspend/resume is only doing port >> suspend/resume or both host and port going to suspend/resume? > > Only the port. However, when _all_ the devices attached to the host > controlluer go into runtime suspend, the controller itself will also be > put into runtime suspend. Would you mind to show me where the program determine controller go into runtime suspend if all devices on it go to suspend? BTW a. if even controller suspended, does that mean all devices on it will be disconnect and re-enumerated when resume? b. is there any usb sysfs file can let us suspend specific port on root or normal hub? appreciate your kind help,
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