• Peter Hurley's avatar
    tty: Remove ASYNC_CLOSING checks in open()/hangup() methods · fef062cb
    Peter Hurley authored
    Since at least before 2.6.30, tty drivers that do not drop the tty lock
    while closing cannot observe ASYNC_CLOSING set while holding the
    tty lock; this includes the tty driver's open() and hangup() methods,
    since the tty core calls these methods holding the tty lock.
    
    For these drivers, waiting for ASYNC_CLOSING to clear while opening
    is not required, since this condition cannot occur. Similarly, even
    when the open() method drops and reacquires the tty lock after
    blocking, ASYNC_CLOSING cannot be set (again, for drivers that
    do not drop the tty lock while closing).
    
    Now that tty port drivers no longer drop the tty lock while closing
    (since 'tty: Remove tty_wait_until_sent_from_close()'), the same
    conditions apply: waiting for ASYNC_CLOSING to clear while opening
    is not required, nor is re-checking ASYNC_CLOSING after dropping and
    reacquiring the tty lock while blocking (eg., in *_block_til_ready()).
    
    Note: The ASYNC_CLOSING flag state is still maintained since several
    bitrotting drivers use it for (dubious) other purposes.
    Signed-off-by: default avatarPeter Hurley <peter@hurleysoftware.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    fef062cb
crisv10.c 118 KB