• Takashi Iwai's avatar
    ALSA: pcm: Bail out when chmap is already present · 8d879be8
    Takashi Iwai authored
    When snd_pcm_add_chmap_ctls() is called to the PCM stream to which a
    chmap has been already assigned, it returns as an error due to the
    conflicting snd_ctl_add() result.  However, this also clears the
    already assigned chmap_kctl field via pcm_chmap_ctl_private_free(),
    and becomes inconsistent in the later operation.
    This patch adds the check of the conflicting chmap kctl before
    actually trying to allocate / assign.  The check failure is treated as
    a kernel warning, as the double call of snd_pcm_add_chmap_ctls() is
    basically a driver bug and having the stack trace would help
    developers to figure out the bad code path.
    Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>