• Xu Biang's avatar
    ALSA: firewire-tascam: add missing unwind goto in snd_tscm_stream_start_duplex() · fb4a624f
    Xu Biang authored
    Smatch Warns:
    sound/firewire/tascam/tascam-stream.c:493 snd_tscm_stream_start_duplex()
    warn: missing unwind goto?
    
    The direct return will cause the stream list of "&tscm->domain" unemptied
    and the session in "tscm" unfinished if amdtp_domain_start() returns with
    an error.
    
    Fix this by changing the direct return to a goto which will empty the
    stream list of "&tscm->domain" and finish the session in "tscm".
    
    The snd_tscm_stream_start_duplex() function is called in the prepare
    callback of PCM. According to "ALSA Kernel API Documentation", the prepare
    callback of PCM will be called many times at each setup. So, if the
    "&d->streams" list is not emptied, when the prepare callback is called
    next time, snd_tscm_stream_start_duplex() will receive -EBUSY from
    amdtp_domain_add_stream() that tries to add an existing stream to the
    domain. The error handling code after the "error" label will be executed
    in this case, and the "&d->streams" list will be emptied. So not emptying
    the "&d->streams" list will not cause an issue. But it is more efficient
    and readable to empty it on the first error by changing the direct return
    to a goto statement.
    
    The session in "tscm" has been begun before amdtp_domain_start(), so it
    needs to be finished when amdtp_domain_start() fails.
    
    Fixes: c281d46a ("ALSA: firewire-tascam: support AMDTP domain")
    Signed-off-by: default avatarXu Biang <xubiang@hust.edu.cn>
    Reviewed-by: default avatarDan Carpenter <error27@gmail.com>
    Acked-by: default avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
    Cc: <stable@vger.kernel.org>
    Link: https://lore.kernel.org/r/20230406132801.105108-1-xubiang@hust.edu.cnSigned-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    fb4a624f
tascam-stream.c 12.9 KB