sound: usb-audio: handle wMaxPacketSize for FIXED_ENDPOINT devices

For audio devices that do not have proper audio descriptors (e.g.,
Edirol UA-20), we use hardcoded parameters from our quirks list.
However, we must still read the maximum packet size from the standard
endpoint descriptor; otherwise, we might use packets that are too big
and therefore rejected by the USB core.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index c709b95..2ab8312 100644 (file)
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -2966,6 +2966,7 @@ static int create_fixed_stream_quirk(struct snd_usb_audio *chip,
                return -EINVAL;
        }
        alts = &iface->altsetting[fp->altset_idx];
+       fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
        usb_set_interface(chip->dev, fp->iface, 0);
        init_usb_pitch(chip->dev, fp->iface, alts, fp);
        init_usb_sample_rate(chip->dev, fp->iface, alts, fp, fp->rate_max);