ALSA: usb-audio: purge needless variable length array
authorTakashi Sakamoto <o-takashi@sakamocchi.jp>
Tue, 21 Feb 2017 22:54:47 +0000 (07:54 +0900)
committerTakashi Iwai <tiwai@suse.de>
Wed, 22 Feb 2017 06:12:23 +0000 (07:12 +0100)
Variable length array is used in 'snd_us16x08_meter_get()', while there
is no need. It's better to purge it because variable length array has
overhead for stack handling.

This commit replaces the array with static length. Sparse generated below
warning.

sound/usb/mixer_us16x08.c:714:18: warning: Variable length array is used.

Fixes: d2bb390a2081 ("ALSA: usb-audio: Tascam US-16x08 DSP mixer quirk")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
sound/usb/mixer_us16x08.c

index 7ac45ec372b904b40f4a31f192326655f9607e4d..73a0b9afdd70293bef0641645f6c30c83ad60e03 100644 (file)
@@ -711,7 +711,7 @@ static int snd_us16x08_meter_get(struct snd_kcontrol *kcontrol,
        struct snd_usb_audio *chip = elem->head.mixer->chip;
        struct snd_us16x08_meter_store *store = elem->private_data;
        u8 meter_urb[64];
-       char tmp[max(sizeof(mix_init_msg1), sizeof(mix_init_msg2))];
+       char tmp[sizeof(mix_init_msg2)] = {0};
 
        if (elem) {
                store = (struct snd_us16x08_meter_store *) elem->private_data;
@@ -721,8 +721,8 @@ static int snd_us16x08_meter_get(struct snd_kcontrol *kcontrol,
 
        switch (kcontrol->private_value) {
        case 0:
-               memcpy(tmp, mix_init_msg1, sizeof(mix_init_msg1));
-               snd_us16x08_send_urb(chip, tmp, 4);
+               snd_us16x08_send_urb(chip, (char *)mix_init_msg1,
+                                    sizeof(mix_init_msg1));
                snd_us16x08_recv_urb(chip, meter_urb,
                        sizeof(meter_urb));
                kcontrol->private_value++;
@@ -740,7 +740,7 @@ static int snd_us16x08_meter_get(struct snd_kcontrol *kcontrol,
        case 3:
                memcpy(tmp, mix_init_msg2, sizeof(mix_init_msg2));
                tmp[2] = snd_get_meter_comp_index(store);
-               snd_us16x08_send_urb(chip, tmp, 10);
+               snd_us16x08_send_urb(chip, tmp, sizeof(mix_init_msg2));
                snd_us16x08_recv_urb(chip, meter_urb,
                        sizeof(meter_urb));
                kcontrol->private_value = 0;