conf: remove alloca() from snd_determine_driver()

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>

diff --git a/src/confmisc.c b/src/confmisc.c
index ae0275ff4de302620994fd913f08650f58f41ea1..3f12e340c46d00163b254b3fb2c3a70f9dea59ba 100644 (file)
--- a/src/confmisc.c
+++ b/src/confmisc.c
@@ -664,7 +664,7 @@ SND_DLSYM_BUILD_VERSION(snd_func_private_string, SND_CONFIG_DLSYM_VERSION_EVALUA
 int snd_determine_driver(int card, char **driver)
 {
        snd_ctl_t *ctl = NULL;
-       snd_ctl_card_info_t *info;
+       snd_ctl_card_info_t info = {0};
        char *res = NULL;
        int err;
 
@@ -674,13 +674,12 @@ int snd_determine_driver(int card, char **driver)
                SNDERR("could not open control for card %i", card);
                goto __error;
        }
-       snd_ctl_card_info_alloca(&info);
-       err = snd_ctl_card_info(ctl, info);
+       err = snd_ctl_card_info(ctl, &info);
        if (err < 0) {
                SNDERR("snd_ctl_card_info error: %s", snd_strerror(err));
                goto __error;
        }
-       res = strdup(snd_ctl_card_info_get_driver(info));
+       res = strdup(snd_ctl_card_info_get_driver(&info));
        if (res == NULL)
                err = -ENOMEM;
        else {