int fd;
        int exclusive_input;
        int stereo_mask;
-       int num_vol_ctls;
-       int vol_ctl[SOUND_MIXER_NRDEVICES];
-       int num_rec_items;
-       int rec_item[SOUND_MIXER_NRDEVICES];
+       unsigned int num_vol_ctls;
+       unsigned int vol_ctl[SOUND_MIXER_NRDEVICES];
+       unsigned int num_rec_items;
+       unsigned int rec_item[SOUND_MIXER_NRDEVICES];
 } snd_ctl_oss_t;
 
 static const char *vol_devices[SOUND_MIXER_NRDEVICES] = {
 {
        snd_ctl_oss_t *oss = ext->private_data;
        const char *name;
-       int i, key;
+       unsigned int i, key;
 
        name = snd_ctl_elem_id_get_name(id);
        if (! strcmp(name, "Capture Source")) {
        return 0;
 }
 
-static int oss_get_integer_info(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key,
+static int oss_get_integer_info(snd_ctl_ext_t *ext ATTRIBUTE_UNUSED,
+                               snd_ctl_ext_key_t key ATTRIBUTE_UNUSED,
                                long *imin, long *imax, long *istep)
 {
        *istep = 0;
        return 0;
 }
 
-static int oss_get_enumerated_info(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key,
+static int oss_get_enumerated_info(snd_ctl_ext_t *ext,
+                                  snd_ctl_ext_key_t key ATTRIBUTE_UNUSED,
                                   unsigned int *items)
 {
        snd_ctl_oss_t *oss = ext->private_data;
        return 0;
 }
 
-static int oss_get_enumerated_name(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key,
-                                  unsigned int item, char *name, size_t name_max_len)
+static int oss_get_enumerated_name(snd_ctl_ext_t *ext,
+                                  snd_ctl_ext_key_t key ATTRIBUTE_UNUSED,
+                                  unsigned int item, char *name,
+                                  size_t name_max_len)
 {
        snd_ctl_oss_t *oss = ext->private_data;
 
        return 0;
 }
 
-static int oss_read_enumerated(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, unsigned int *items)
+static int oss_read_enumerated(snd_ctl_ext_t *ext,
+                              snd_ctl_ext_key_t key ATTRIBUTE_UNUSED,
+                              unsigned int *items)
 {
        snd_ctl_oss_t *oss = ext->private_data;
-       int i, val;
+       unsigned int i, val;
 
        *items = 0;
        if (ioctl(oss->fd, SOUND_MIXER_READ_RECSRC, &val) < 0)
        }
 }
 
-static int oss_write_enumerated(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key,
+static int oss_write_enumerated(snd_ctl_ext_t *ext,
+                               snd_ctl_ext_key_t key ATTRIBUTE_UNUSED,
                                unsigned int *items)
 {
        snd_ctl_oss_t *oss = ext->private_data;
        return 1;
 }
 
-static int oss_read_event(snd_ctl_ext_t *ext, snd_ctl_elem_id_t *id,
-                         unsigned int *event_mask)
+static int oss_read_event(snd_ctl_ext_t *ext ATTRIBUTE_UNUSED,
+                         snd_ctl_elem_id_t *id ATTRIBUTE_UNUSED,
+                         unsigned int *event_mask ATTRIBUTE_UNUSED)
 {
        return -EAGAIN;
 }