• Johan Hovold's avatar
    USB: serial: remove multi-urb write from generic driver · c23e5fc1
    Johan Hovold authored
    Remove multi-urb write from the generic driver and simplify the
    prepare_write_buffer prototype:
    
    	int (*prepare_write_buffer)(struct usb_serial_port *port,
    						void *dest, size_t size);
    
    The default implementation simply fills dest with data from port write
    fifo but drivers can override it if they need to process the outgoing
    data (e.g. add headers).
    
    Turn ftdi_sio into a generic fifo-based driver, which lowers CPU usage
    significantly for small writes while retaining maximum throughput.
    Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
    c23e5fc1
generic.c 13.1 KB