pcm: remove alloca() from softvol_load_control()

Both of alloca() and automatic variables keeps 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 2016-07-14 23:07:37 +09:00 committed by Takashi Iwai
parent 8306bb2b6a
commit 349920f93d

View file

@ -702,17 +702,16 @@ static int softvol_load_control(snd_pcm_t *pcm, snd_pcm_softvol_t *svol,
int resolution) int resolution)
{ {
char tmp_name[32]; char tmp_name[32];
snd_pcm_info_t *info; snd_pcm_info_t info = {0};
snd_ctl_elem_info_t *cinfo; snd_ctl_elem_info_t cinfo = {0};
int err; int err;
unsigned int i; unsigned int i;
if (ctl_card < 0) { if (ctl_card < 0) {
snd_pcm_info_alloca(&info); err = snd_pcm_info(pcm, &info);
err = snd_pcm_info(pcm, info);
if (err < 0) if (err < 0)
return err; return err;
ctl_card = snd_pcm_info_get_card(info); ctl_card = snd_pcm_info_get_card(&info);
if (ctl_card < 0) { if (ctl_card < 0) {
SNDERR("No card defined for softvol control"); SNDERR("No card defined for softvol control");
return -EINVAL; return -EINVAL;
@ -737,46 +736,45 @@ static int softvol_load_control(snd_pcm_t *pcm, snd_pcm_softvol_t *svol,
svol->zero_dB_val = (min_dB / (min_dB - max_dB)) * svol->zero_dB_val = (min_dB / (min_dB - max_dB)) *
svol->max_val; svol->max_val;
snd_ctl_elem_info_alloca(&cinfo); snd_ctl_elem_info_set_id(&cinfo, ctl_id);
snd_ctl_elem_info_set_id(cinfo, ctl_id); if ((err = snd_ctl_elem_info(svol->ctl, &cinfo)) < 0) {
if ((err = snd_ctl_elem_info(svol->ctl, cinfo)) < 0) {
if (err != -ENOENT) { if (err != -ENOENT) {
SNDERR("Cannot get info for CTL %s", tmp_name); SNDERR("Cannot get info for CTL %s", tmp_name);
return err; return err;
} }
err = add_user_ctl(svol, cinfo, cchannels); err = add_user_ctl(svol, &cinfo, cchannels);
if (err < 0) { if (err < 0) {
SNDERR("Cannot add a control"); SNDERR("Cannot add a control");
return err; return err;
} }
} else { } else {
if (! (cinfo->access & SNDRV_CTL_ELEM_ACCESS_USER)) { if (! (cinfo.access & SNDRV_CTL_ELEM_ACCESS_USER)) {
/* hardware control exists */ /* hardware control exists */
return 1; /* notify */ return 1; /* notify */
} else if ((cinfo->type != SND_CTL_ELEM_TYPE_INTEGER && } else if ((cinfo.type != SND_CTL_ELEM_TYPE_INTEGER &&
cinfo->type != SND_CTL_ELEM_TYPE_BOOLEAN) || cinfo.type != SND_CTL_ELEM_TYPE_BOOLEAN) ||
cinfo->count != (unsigned int)cchannels || cinfo.count != (unsigned int)cchannels ||
cinfo->value.integer.min != 0 || cinfo.value.integer.min != 0 ||
cinfo->value.integer.max != resolution - 1) { cinfo.value.integer.max != resolution - 1) {
err = snd_ctl_elem_remove(svol->ctl, &cinfo->id); err = snd_ctl_elem_remove(svol->ctl, &cinfo.id);
if (err < 0) { if (err < 0) {
SNDERR("Control %s mismatch", tmp_name); SNDERR("Control %s mismatch", tmp_name);
return err; return err;
} }
/* reset numid */ /* reset numid */
snd_ctl_elem_info_set_id(cinfo, ctl_id); snd_ctl_elem_info_set_id(&cinfo, ctl_id);
if ((err = add_user_ctl(svol, cinfo, cchannels)) < 0) { if ((err = add_user_ctl(svol, &cinfo, cchannels)) < 0) {
SNDERR("Cannot add a control"); SNDERR("Cannot add a control");
return err; return err;
} }
} else if (svol->max_val > 1) { } else if (svol->max_val > 1) {
/* check TLV availability */ /* check TLV availability */
unsigned int tlv[4]; unsigned int tlv[4];
err = snd_ctl_elem_tlv_read(svol->ctl, &cinfo->id, tlv, err = snd_ctl_elem_tlv_read(svol->ctl, &cinfo.id, tlv,
sizeof(tlv)); sizeof(tlv));
if (err < 0) if (err < 0)
add_tlv_info(svol, cinfo); add_tlv_info(svol, &cinfo);
} }
} }