mixer: remove alloca() from elem_write_enum()

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 09:23:20 +09:00 committed by Takashi Iwai
parent 5ca104cf15
commit bd09e4790c

View file

@ -532,7 +532,7 @@ static int elem_write_route(selem_none_t *s, int dir, selem_ctl_type_t type)
static int elem_write_enum(selem_none_t *s) static int elem_write_enum(selem_none_t *s)
{ {
snd_ctl_elem_value_t *ctl; snd_ctl_elem_value_t ctl = {0};
unsigned int idx; unsigned int idx;
int err; int err;
int type; int type;
@ -546,13 +546,12 @@ static int elem_write_enum(selem_none_t *s)
else if (s->selem.caps & SM_CAP_CENUM) else if (s->selem.caps & SM_CAP_CENUM)
type = CTL_CAPTURE_ENUM; type = CTL_CAPTURE_ENUM;
c = &s->ctls[type]; 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_enumerated(ctl, idx, snd_ctl_elem_value_set_enumerated(&ctl, idx,
(unsigned int)s->str[0].vol[idx]); (unsigned int)s->str[0].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;
} }