mixer: remove alloca() from enum_item_name_ops()

Both of alloca() and automatic variables keep storages on stack, while
the former generates more instructions than the latter. It's better to use
the latter if the size of storage is computable at pre-compile or compile
time; i.e. just for structures.

This commit obsolete usages of alloca() with automatic variables.

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

diff --git a/src/mixer/simple_none.c b/src/mixer/simple_none.c
index 0799ceb3ee15355cd3ca1deb4e425a5ae60408a7..ab2b1515147c4798204edb76f8d7af5dec369bb3 100644 (file)
--- a/src/mixer/simple_none.c
+++ b/src/mixer/simple_none.c
@@ -1313,7 +1313,7 @@ static int enum_item_name_ops(snd_mixer_elem_t *elem,
                              size_t maxlen, char *buf)
 {
        selem_none_t *s = snd_mixer_elem_get_private(elem);
-       snd_ctl_elem_info_t *info;
+       snd_ctl_elem_info_t info = {0};
        snd_hctl_elem_t *helem;
        int type;
 
@@ -1330,11 +1330,10 @@ static int enum_item_name_ops(snd_mixer_elem_t *elem,
        assert(helem);
        if (item >= (unsigned int)s->ctls[type].max)
                return -EINVAL;
-       snd_ctl_elem_info_alloca(&info);
-       snd_hctl_elem_info(helem, info);
-       snd_ctl_elem_info_set_item(info, item);
-       snd_hctl_elem_info(helem, info);
-       strncpy(buf, snd_ctl_elem_info_get_item_name(info), maxlen);
+       snd_hctl_elem_info(helem, &info);
+       snd_ctl_elem_info_set_item(&info, item);
+       snd_hctl_elem_info(helem, &info);
+       strncpy(buf, snd_ctl_elem_info_get_item_name(&info), maxlen);
        return 0;
 }