• Ganesh Varadarajan's avatar
    USB serial drivers · c3cdeb68
    Ganesh Varadarajan authored
    Several functions in the serial drivers can be called from bottom
    half or interrupt context. They must use the GFP_ATOMIC flag for
    calls to kmalloc() and usb_submit_urb().
      
    Functions which must use GFP_ATOMIC:
    1. All *_callback() functions.
    2. Any code which is inside a spinlock.
    3. write(), throttle(), unthrottle(), which may be called by
       the line discipline in bottom half context.
      
    Functions which can use GFP_KERNEL:
    1. open(), close(), startup(), shutdown(), set_termios().
    c3cdeb68
ftdi_sio.c 30.4 KB