static int check_event(struct elem_set_trial *trial, unsigned int mask,
unsigned int expected_count)
{
struct pollfd pfds;
int count;
unsigned short revents;
snd_ctl_event_t *event;
int err;
snd_ctl_event_alloca(&event);
if (snd_ctl_poll_descriptors_count(trial->handle) != 1)
return -ENXIO;
if (snd_ctl_poll_descriptors(trial->handle, &pfds, 1) != 1)
return -ENXIO;
while (expected_count > 0) {
count = poll(&pfds, 1, 1000);
if (count < 0)
return errno;
/* Some events are already supplied. */
if (count == 0)
return -ETIMEDOUT;
err = snd_ctl_poll_descriptors_revents(trial->handle, &pfds,
count, &revents);
if (err < 0)
return err;
if (revents & POLLERR)
return -EIO;
if (!(revents & POLLIN))
continue;
err = snd_ctl_read(trial->handle, event);
if (err < 0)
return err;
if (snd_ctl_event_get_type(event) != SND_CTL_EVENT_ELEM)
continue;
/*
* I expect each event is generated separately to the same
* element.
*/
if (!(snd_ctl_event_elem_get_mask(event) & mask))
continue;
--expected_count;
}
if (expected_count != 0)
return -EIO;
return 0;
}
static int handle_event(int hwdep_fd, snd_ctl_t *ctl)
{
snd_ctl_event_t *event;
unsigned int mask;
int err;
snd_ctl_event_alloca(&event);
err = snd_ctl_read(ctl, event);
if (err < 0) {
fprintf(stderr, "Cannot read event from ctl %s\n", snd_ctl_name(ctl));
return err;
}
if (snd_ctl_event_get_type(event) != SND_CTL_EVENT_ELEM) {
return 0;
}
// Filter events
mask = snd_ctl_event_elem_get_mask(event);
if (mask & SND_CTL_EVENT_MASK_VALUE) {
const char *event_name = snd_ctl_event_elem_get_name(event);
if (!strcmp(event_name, HEADPHONE_SWITCH_NAME)) {
// If headphones were plugged, mute LFE
set_headphones_plugged(&headphones_plugged);
if (headphones_plugged) {
set_lfe_volume(hwdep_fd, 0);
}
} else if (!headphones_plugged && !strcmp(event_name, MASTER_VOLUME_NAME)) {
// If headphones are unplugged and master volume changed, adjust LFE volume
set_lfe_volume(hwdep_fd, get_master_volume());
}
}
return 0;
}
