ALSA: snd-usb-usx2y: remove bogus frame checks

[Guido Aulisi <guido.aulisi@gmail.com>]

Hi,
I did some more testing on my US122:

I used my patch (see below) and it worked (with default nrpack=4), but I
got "should not be here with counts=42" errors, then after some time the
kernel crashed, but I couldn't copy the trace.

Then I set nrpack=1 and I got no "should not be here..." and it was more
stable, no crash. I only checked playback, not recording, nor MIDI, with
aplay I played some songs for about one hour...

I hope this can be useful. But I think there are other bugs in this
driver.

Ciao
Guido Aulisi

The patch is:

diff --git a/sound/usb/usx2y/usbusx2yaudio.c b/sound/usb/usx2y/usbusx2yaudio.c
index 63fb521..cd16fcc 100644
--- a/sound/usb/usx2y/usbusx2yaudio.c
+++ b/sound/usb/usx2y/usbusx2yaudio.c
@@ -328,7 +328,7 @@ static void i_usX2Y_urb_complete(struct urb *urb)
                usX2Y_error_urb_status(usX2Y, subs, urb);
                return;
        }
-       if (likely((urb->start_frame & 0xFFFF) == (usX2Y->wait_iso_frame & 0xFFFF)))
+       if (likely((urb->start_frame & 0x03FF) == (usX2Y->wait_iso_frame & 0x03FF)))
                subs->completed_urb = urb;
        else {
                usX2Y_error_sequence(usX2Y, subs, urb);