ALSA: usb-audio: Refactor ignore_ctl_error checks

Introduce an internal helper macro for avoiding many open codes.

The only slight behavior change is in a couple of get ballcks where
the value is reset at error no matter whether ignore_ctl_error is set
or not.  Actually this is even safer than before.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index c6209ce..a4fbfff 100644 (file)
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -136,6 +136,10 @@ check_mapped_name(const struct usbmix_name_map *p, char *buf, int buflen)
        return strlcpy(buf, p->name, buflen);
 }
 
+/* ignore the error value if ignore_ctl_error flag is set */
+#define filter_error(cval, err) \
+       ((cval)->mixer->ignore_ctl_error ? 0 : (err))
+
 /* check whether the control should be ignored */
 static inline int
 check_ignored_ctl(const struct usbmix_name_map *p)
@@ -1088,7 +1092,7 @@ static int mixer_ctl_feature_get(struct snd_kcontrol *kcontrol,
                                continue;
                        err = snd_usb_get_cur_mix_value(cval, c + 1, cnt, &val);
                        if (err < 0)
-                               return cval->mixer->ignore_ctl_error ? 0 : err;
+                               return filter_error(cval, err);
                        val = get_relative_value(cval, val);
                        ucontrol->value.integer.value[cnt] = val;
                        cnt++;
@@ -1098,7 +1102,7 @@ static int mixer_ctl_feature_get(struct snd_kcontrol *kcontrol,
                /* master channel */
                err = snd_usb_get_cur_mix_value(cval, 0, 0, &val);
                if (err < 0)
-                       return cval->mixer->ignore_ctl_error ? 0 : err;
+                       return filter_error(cval, err);
                val = get_relative_value(cval, val);
                ucontrol->value.integer.value[0] = val;
        }
@@ -1120,7 +1124,7 @@ static int mixer_ctl_feature_put(struct snd_kcontrol *kcontrol,
                                continue;
                        err = snd_usb_get_cur_mix_value(cval, c + 1, cnt, &oval);
                        if (err < 0)
-                               return cval->mixer->ignore_ctl_error ? 0 : err;
+                               return filter_error(cval, err);
                        val = ucontrol->value.integer.value[cnt];
                        val = get_abs_value(cval, val);
                        if (oval != val) {
@@ -1133,7 +1137,7 @@ static int mixer_ctl_feature_put(struct snd_kcontrol *kcontrol,
                /* master channel */
                err = snd_usb_get_cur_mix_value(cval, 0, 0, &oval);
                if (err < 0)
-                       return cval->mixer->ignore_ctl_error ? 0 : err;
+                       return filter_error(cval, err);
                val = ucontrol->value.integer.value[0];
                val = get_abs_value(cval, val);
                if (val != oval) {
@@ -1628,12 +1632,10 @@ static int mixer_ctl_procunit_get(struct snd_kcontrol *kcontrol,
        int err, val;
 
        err = get_cur_ctl_value(cval, cval->control << 8, &val);
-       if (err < 0 && cval->mixer->ignore_ctl_error) {
+       if (err < 0) {
                ucontrol->value.integer.value[0] = cval->min;
-               return 0;
+               return filter_error(cval, err);
        }
-       if (err < 0)
-               return err;
        val = get_relative_value(cval, val);
        ucontrol->value.integer.value[0] = val;
        return 0;
@@ -1647,11 +1649,8 @@ static int mixer_ctl_procunit_put(struct snd_kcontrol *kcontrol,
        int val, oval, err;
 
        err = get_cur_ctl_value(cval, cval->control << 8, &oval);
-       if (err < 0) {
-               if (cval->mixer->ignore_ctl_error)
-                       return 0;
-               return err;
-       }
+       if (err < 0)
+               return filter_error(cval, err);
        val = ucontrol->value.integer.value[0];
        val = get_abs_value(cval, val);
        if (val != oval) {
@@ -1923,11 +1922,8 @@ static int mixer_ctl_selector_get(struct snd_kcontrol *kcontrol,
 
        err = get_cur_ctl_value(cval, cval->control << 8, &val);
        if (err < 0) {
-               if (cval->mixer->ignore_ctl_error) {
-                       ucontrol->value.enumerated.item[0] = 0;
-                       return 0;
-               }
-               return err;
+               ucontrol->value.enumerated.item[0] = 0;
+               return filter_error(cval, err);
        }
        val = get_relative_value(cval, val);
        ucontrol->value.enumerated.item[0] = val;
@@ -1942,11 +1938,8 @@ static int mixer_ctl_selector_put(struct snd_kcontrol *kcontrol,
        int val, oval, err;
 
        err = get_cur_ctl_value(cval, cval->control << 8, &oval);
-       if (err < 0) {
-               if (cval->mixer->ignore_ctl_error)
-                       return 0;
-               return err;
-       }
+       if (err < 0)
+               return filter_error(cval, err);
        val = ucontrol->value.enumerated.item[0];
        val = get_abs_value(cval, val);
        if (val != oval) {