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>

diff --git a/sound/firewire/bebob/bebob_maudio.c b/sound/firewire/bebob/bebob_maudio.c
index 42e6f22156f022831ea163f1736c4bf34917622f..d6d6ff8cb8dd3923124781a3c29922a89fd2002f 100644 (file)
--- 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;