mixer: remove alloca() from elem_write_volume()

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>
This commit is contained in:
Takashi Sakamoto 2016-07-15 09:23:15 +09:00 committed by Takashi Iwai
parent 32393c67ab
commit 1c11f334e7

View file

@ -467,17 +467,16 @@ static int selem_read(snd_mixer_elem_t *elem)
static int elem_write_volume(selem_none_t *s, int dir, selem_ctl_type_t type) static int elem_write_volume(selem_none_t *s, int dir, selem_ctl_type_t type)
{ {
snd_ctl_elem_value_t *ctl; snd_ctl_elem_value_t ctl = {0};
unsigned int idx; unsigned int idx;
int err; int err;
selem_ctl_t *c = &s->ctls[type]; selem_ctl_t *c = &s->ctls[type];
snd_ctl_elem_value_alloca(&ctl); if ((err = snd_hctl_elem_read(c->elem, &ctl)) < 0)
if ((err = snd_hctl_elem_read(c->elem, ctl)) < 0)
return err; return err;
for (idx = 0; idx < c->values; idx++) for (idx = 0; idx < c->values; idx++)
snd_ctl_elem_value_set_integer(ctl, idx, snd_ctl_elem_value_set_integer(&ctl, idx,
from_user(s, dir, c, s->str[dir].vol[idx])); from_user(s, dir, c, s->str[dir].vol[idx]));
if ((err = snd_hctl_elem_write(c->elem, ctl)) < 0) if ((err = snd_hctl_elem_write(c->elem, &ctl)) < 0)
return err; return err;
return 0; return 0;
} }