On Fri, Aug 07, 2015 at 07:26:15PM +0900, arun k wrote: > Hi, > > I am stuck with the above issue, > I have some doubts regarding USB - Generic driver > 1. Could you please explain me why USB - Generic driver is slow ? Because it was designed that way, it is not for high-speed data throughput at all. It is a stop-gap measure for dumb usb devices that want to emulate a serial connection. If you need a "real" driver, to handle high rates of data, you will need to write a new driver for it. > 2. Now I am try to study USB - Generic driver implementation , I am > confused with the function usb_serial_generic_read_bulk_callback() , > could you please tell me from where this function is calling ? I recommend reading the USB chapter in the Linux Device Drivers book (version 3, free online) to understand how USB drivers work. After that, the answer should be obvious (hint, look at where that function pointer is assigned to something...) > 3. If you have any detailed doc regarding the implementation of USB - > Generic serial driver, Please send to me, The source code is pretty well documented :) thanks, greg k-h -- 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