Hi Greg KH, I have a query regarding the USB-FS driver, usb/core/devio.c. It looks like it takes a PM ref-count on the USB device in its .open() and release the PM ref-count on the USB device in its .release(). As a result of this, the USB suspend (L2) does not seem to happen, even if all the interface drivers of a composite USB device report "idle" to USB core driver. The USB suspend seem to happen only when the caller in user-space (in our case) closes the device file. Is this correct understanding? If yes, could you please help understand - 1. Any specific reason to choose this design approach? Apologies, but "git blame" does not reveal much information (or maybe I did not do git blame on correct kernel version). 2. Is it possible to modify this driver to take PM ref-count on USB device, only when user-space is actively interacting with the USB device (so in open/close and appropriate ioctl calls, with special handling for async URB submission)? 3. Will (2) break any known existing device(s)? Please feel free to correct if any of above information/questions are incorrect or incorrectly understood. Best Regards, Mayuresh
