ALSA: bebob: Correction for return value of .put callback

This commit is for correction of my misunderstanding about return value of
.put callback in ALSA Control interface.

According to 'Writing ALSA Driver' (*1), return value of the callback has
three patterns; 1: changed, 0: not changed, an negative value: fatal error.

But I misunderstood that it's boolean; zero or nonzero.

*1: Writing an ALSA Driver (2005, Takashi Iwai)
http://www.alsa-project.org/main/index.php/ALSA_Driver_Documentation

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 19 insertions, 7 deletions

diff --git a/sound/firewire/bebob/bebob_maudio.c b/sound/firewire/bebob/bebob_maudio.c
index 42e6f22156f0..d6d6ff8cb8dd 100644
--- a/sound/firewire/bebob/bebob_maudio.c
+++ b/sound/firewire/bebob/bebob_maudio.c
@@ -391,7 +391,10 @@ static int special_clk_ctl_put(struct snd_kcontrol *kctl,
                                          params->clk_lock);
         mutex_unlock(&bebob->mutex);
 
-        return err >= 0;
+        if (err >= 0)
+                err = 1;
+
+        return err;
 }
 static struct snd_kcontrol_new special_clk_ctl = {
         .name   = "Clock Source",
@@ -491,14 +494,16 @@ static int special_dig_in_iface_ctl_set(struct snd_kcontrol *kctl,
         unsigned int id, dig_in_fmt, dig_in_iface;
         int err;
 
-        mutex_lock(&bebob->mutex);
-
         id = uval->value.enumerated.item[0];
+        if (id >= ARRAY_SIZE(special_dig_in_iface_labels))
+                return -EINVAL;
 
         /* decode user value */
         dig_in_fmt = (id >> 1) & 0x01;
         dig_in_iface = id & 0x01;
 
+        mutex_lock(&bebob->mutex);
+
         err = avc_maudio_set_special_clk(bebob,
                                          params->clk_src,
                                          dig_in_fmt,
@@ -508,14 +513,17 @@ static int special_dig_in_iface_ctl_set(struct snd_kcontrol *kctl,
                 goto end;
 
         /* For ADAT, optical interface is only available. */
-        if (params->dig_in_fmt > 0)
+        if (params->dig_in_fmt > 0) {
+                err = 1;
                 goto end;
+        }
 
         /* For S/PDIF, optical/coaxial interfaces are selectable. */
         err = avc_audio_set_selector(bebob->unit, 0x00, 0x04, dig_in_iface);
         if (err < 0)
                 dev_err(&bebob->unit->device,
                         "fail to set digital input interface: %d\n", err);
+        err = 1;
 end:
         special_stream_formation_set(bebob);
         mutex_unlock(&bebob->mutex);
@@ -567,16 +575,20 @@ static int special_dig_out_iface_ctl_set(struct snd_kcontrol *kctl,
         unsigned int id;
         int err;
 
-        mutex_lock(&bebob->mutex);
-
         id = uval->value.enumerated.item[0];
+        if (id >= ARRAY_SIZE(special_dig_out_iface_labels))
+                return -EINVAL;
+
+        mutex_lock(&bebob->mutex);
 
         err = avc_maudio_set_special_clk(bebob,
                                          params->clk_src,
                                          params->dig_in_fmt,
                                          id, params->clk_lock);
-        if (err >= 0)
+        if (err >= 0) {
                 special_stream_formation_set(bebob);
+                err = 1;
+        }
 
         mutex_unlock(&bebob->mutex);
         return err;