HI Alen , Thanx for the reply . it will certainly help my cause . But my problem is , before a userspace program send the command echo N >/sys/bus/usb/devices/.../bConfigurationValue to the device , usb host will already select default mass storage configuration on device plugin (device exposes default 1st configuration as mass storage and we have no control over device firmware ). this is not desired . what i want is , usb host on detecting this multi configuration device , instead of selecting default configuration , invoke some userspace binary where depending upon "echo N >/sys/bus/usb/devices/.../bConfigurationValue to the device " desired configuration can be selected . so how i can handle this signalling from usb host to userspace . thanx for reply once again Regards Amit Nagal On Thu, Jun 10, 2010 at 8:11 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Thu, 10 Jun 2010, Amit Nagal wrote: > >> Hi , >> >> >> i am working on linux usb host side . >> >> the interfacing usb device supports 2 usb configurations . >> >> default is 1) mass storage . >> >> other is 2) vendor specific configuration . >> >> if we connect such device to usb host , >> >> is it possible to have the following : >> >> 1) usb core queries device for total no of configurations supported . >> >> and then instead of selecting the first default mass storage >> configuration from the device , >> >> usb core notifies some user space program regarding usb >> configurations available >> >> and depending upon user input to user space program , >> >> mass storage configuration or the vendor specific configuration is >> selected from user space . >> >> how we can select on the fly from user space program the desired usb >> configuration from a multi >> >> configuration usb device . what user space interface we can use . and >> what modifications >> >> need to be done in usb core . > > A program can select configuration N by writing to the appropriate file > in sysfs. For example: > > echo N >/sys/bus/usb/devices/.../bConfigurationValue > > where "..." is the path for the device you want to set. No > modifications to usbcore are needed. > > 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
