Commit 447cae58 authored by Kirill Marinushkin's avatar Kirill Marinushkin Committed by Takashi Iwai

ALSA: usb-audio: Fix UAC2 get_ctl request with a RANGE attribute

The layout of the UAC2 Control request and response varies depending on
the request type. With the current implementation, only the Layout 2
Parameter Block (with the 2-byte sized RANGE attribute) is handled
properly. For the Control requests with the 1-byte sized RANGE attribute
(Bass Control, Mid Control, Tremble Control), the response is parsed
incorrectly.

This commit:
* fixes the wLength field value in the request
* fixes parsing the range values from the response

Fixes: 23caaf19 ("ALSA: usb-mixer: Add support for Audio Class v2.0")
Signed-off-by: default avatarKirill Marinushkin <k.marinushkin@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 2bda7141
......@@ -347,17 +347,20 @@ static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request,
int validx, int *value_ret)
{
struct snd_usb_audio *chip = cval->head.mixer->chip;
unsigned char buf[4 + 3 * sizeof(__u32)]; /* enough space for one range */
/* enough space for one range */
unsigned char buf[sizeof(__u16) + 3 * sizeof(__u32)];
unsigned char *val;
int idx = 0, ret, size;
int idx = 0, ret, val_size, size;
__u8 bRequest;
val_size = uac2_ctl_value_size(cval->val_type);
if (request == UAC_GET_CUR) {
bRequest = UAC2_CS_CUR;
size = uac2_ctl_value_size(cval->val_type);
size = val_size;
} else {
bRequest = UAC2_CS_RANGE;
size = sizeof(buf);
size = sizeof(__u16) + 3 * val_size;
}
memset(buf, 0, sizeof(buf));
......@@ -390,16 +393,17 @@ static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request,
val = buf + sizeof(__u16);
break;
case UAC_GET_MAX:
val = buf + sizeof(__u16) * 2;
val = buf + sizeof(__u16) + val_size;
break;
case UAC_GET_RES:
val = buf + sizeof(__u16) * 3;
val = buf + sizeof(__u16) + val_size * 2;
break;
default:
return -EINVAL;
}
*value_ret = convert_signed_value(cval, snd_usb_combine_bytes(val, sizeof(__u16)));
*value_ret = convert_signed_value(cval,
snd_usb_combine_bytes(val, val_size));
return 0;
}
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment