• Bjørn Mork's avatar
    net: cdc_ncm/cdc_mbim: adding NCM protocol statistics · beeecd42
    Bjørn Mork authored
    To have an idea of the effects of the protocol coalescing
    it's useful to have some counters showing the different
    aspects.
    
    Due to the asymmetrical usbnet interface the netdev
    rx_bytes counter has been counting real received payload,
    while the tx_bytes counter has included the NCM/MBIM
    framing overhead. This overhead can be many times the
    payload because of the aggressive padding strategy of
    this driver, and will vary a lot depending on device
    and traffic.
    
    With very few exceptions, users are only interested in
    the payload size.  Having an somewhat accurate payload
    byte counter is particularly important for mobile
    broadband devices, which many NCM devices and of course
    all MBIM devices are. Users and userspace applications
    will use this counter to monitor account quotas.
    
    Having protocol specific counters for the overhead, we are
    now able to correct the tx_bytes netdev counter so that
    it shows the real payload
    Signed-off-by: default avatarBjørn Mork <bjorn@mork.no>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    beeecd42
cdc_ncm.c 44.1 KB