[PATCH 4.4 76/99] ALSA: firewire-tascam: handle error code when getting current source of clock

[Greg Kroah-Hartman]

From: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>

commit 2617120f4de6d0423384e0e86b14c78b9de84d5a upstream.

The return value of snd_tscm_stream_get_clock() is ignored. This commit
checks the value and handle error.

Fixes: e453df44f0d6 ("ALSA: firewire-tascam: add PCM functionality")
Cc: <stable@xxxxxxxxxxxxxxx> # v4.4+
Signed-off-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20190910135152.29800-2-o-takashi@xxxxxxxxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 sound/firewire/tascam/tascam-pcm.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/sound/firewire/tascam/tascam-pcm.c
+++ b/sound/firewire/tascam/tascam-pcm.c
@@ -81,6 +81,9 @@ static int pcm_open(struct snd_pcm_subst
 		goto err_locked;
 
 	err = snd_tscm_stream_get_clock(tscm, &clock);
+	if (err < 0)
+		goto err_locked;
+
 	if (clock != SND_TSCM_CLOCK_INTERNAL ||
 	    amdtp_stream_pcm_running(&tscm->rx_stream) ||
 	    amdtp_stream_pcm_running(&tscm->tx_stream)) {