Am Montag, 11. Januar 2010 20:32:14 schrieb Alan Stern: > I still don't understand. First, why would usb_autosuspend_device(), > usb_autoresume_device(), or usb_try_autosuspend_device() do > copy_from_user()? As a general rule, they don't have a meaningful user > context. Second, why would the driver need to take the device lock? I don't know, but quoting you (Documentation/usb/power-management.txt): If a driver wants to block all suspend/resume calls during some critical section, the best way is to lock the device and call usb_autopm_get_interface() (and do the reverse at the end of the critical section). Holding the device semaphore will block all external PM calls, and the usb_autopm_get_interface() will prevent any internal PM calls, even if it fails. (Exercise: Why?) Regards Oliver -- 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
