alsactl: fix the check for additional elements

The driver may export only write-only elements. The previous
heuristics code do not handle this use case correctly.
Iterate through all elements and skip the write-only ones.

Fixes: https://github.com/alsa-project/alsa-utils/issues/122
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
This commit is contained in:
Jaroslav Kysela 2021-12-03 11:09:54 +01:00
parent 3b1b6863e7
commit 257f3063fa

View file

@ -1482,13 +1482,19 @@ static int set_controls(int card, snd_config_t *top, int doit)
{
snd_ctl_t *handle;
snd_ctl_card_info_t *info;
snd_ctl_elem_list_t *list;
snd_ctl_elem_info_t *elem_info;
snd_ctl_elem_id_t *elem_id;
snd_config_t *control;
snd_config_iterator_t i, next;
int err, maxnumid = -1;
int err, maxnumid = -1, maxnumid2 = -1;
unsigned int idx, count = 0;
char name[32], tmpid[16];
const char *id;
snd_ctl_card_info_alloca(&info);
snd_ctl_elem_list_alloca(&list);
snd_ctl_elem_info_alloca(&elem_info);
snd_ctl_elem_id_alloca(&elem_id);
sprintf(name, "hw:%d", card);
dbg("device='%s', doit=%i", name, doit);
err = snd_ctl_open(&handle, name, 0);
@ -1528,22 +1534,54 @@ static int set_controls(int card, snd_config_t *top, int doit)
goto _close;
}
dbg("maxnumid=%i", maxnumid);
if (doit)
goto _close;
err = snd_ctl_elem_list(handle, list);
if (err < 0) {
error("Cannot determine controls: %s", snd_strerror(err));
goto _close;
}
count = snd_ctl_elem_list_get_count(list);
dbg("list count: %u", count);
if (count == 0)
goto _check;
snd_ctl_elem_list_set_offset(list, 0);
if (snd_ctl_elem_list_alloc_space(list, count) < 0) {
error("No enough memory...");
goto _close;
}
if ((err = snd_ctl_elem_list(handle, list)) < 0) {
error("Cannot determine controls (2): %s", snd_strerror(err));
goto _free;
}
maxnumid2 = 0;
/* skip non-readable elements */
for (idx = 0; idx < count; ++idx) {
snd_ctl_elem_info_clear(elem_info);
snd_ctl_elem_list_get_id(list, idx, elem_id);
snd_ctl_elem_info_set_id(elem_info, elem_id);
if (snd_ctl_elem_info(handle, elem_info) == 0) {
if (!snd_ctl_elem_info_is_readable(elem_info))
continue;
maxnumid2++;
}
}
/* check if we have additional controls in driver */
/* in this case we should go through init procedure */
if (!doit && maxnumid >= 0) {
snd_ctl_elem_info_t *info;
snd_ctl_elem_info_alloca(&info);
snd_ctl_elem_info_set_numid(info, maxnumid+1);
if (snd_ctl_elem_info(handle, info) == 0) {
_check:
dbg("maxnumid=%i maxnumid2=%i", maxnumid, maxnumid2);
if (maxnumid >= 0 && maxnumid != maxnumid2) {
/* not very informative */
/* but value is used for check only */
err = -EAGAIN;
dbg("more controls than maxnumid?");
goto _close;
}
}
_free:
if (count >= 0)
snd_ctl_elem_list_free_space(list);
_close:
snd_ctl_close(handle);
dbg("result code: %i", err);