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  • Jacob Keller's avatar
    igb: check for Tx timestamp timeouts during watchdog · e5f36ad1
    Jacob Keller authored
    The igb driver has logic to handle only one Tx timestamp at a time,
    using a state bit lock to avoid multiple requests at once.
    It may be possible, if incredibly unlikely, that a Tx timestamp event is
    requested but never completes. Since we use an interrupt scheme to
    determine when the Tx timestamp occurred we would never clear the state
    bit in this case.
    Add an igb_ptp_tx_hang() function similar to the already existing
    igb_ptp_rx_hang() function. This function runs in the watchdog routine
    and makes sure we eventually recover from this case instead of
    permanently disabling Tx timestamps.
    Note: there is no currently known way to cause this without hacking the
    driver code to force it.
    Signed-off-by: default avatarJacob Keller <>
    Tested-by: default avatarAaron Brown <>
    Signed-off-by: default avatarJeff Kirsher <>