[ALSA] usb-audio - sanity-check sync feedback frequency values

USB generic driver
Check that the synchronization feedback frequency values returned by the
device are more or less near the nominal frequency.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
This commit is contained in:
Clemens Ladisch 2005-05-13 07:44:13 +02:00 committed by Jaroslav Kysela
parent 7291548df6
commit 50cdbf1519
1 changed files with 9 additions and 13 deletions

View File

@ -452,17 +452,11 @@ static int retire_playback_sync_urb(snd_usb_substream_t *subs,
if (urb->iso_frame_desc[0].status == 0 &&
urb->iso_frame_desc[0].actual_length == 3) {
f = combine_triple((u8*)urb->transfer_buffer) << 2;
#if 0
if (f < subs->freqn - (subs->freqn>>3) || f > subs->freqmax) {
snd_printd(KERN_WARNING "requested frequency %d (%u,%03uHz) out of range (current nominal %d (%u,%03uHz))\n",
f, f >> 14, (f & ((1 << 14) - 1) * 1000) / ((1 << 14) - 1),
subs->freqn, subs->freqn >> 14, (subs->freqn & ((1 << 14) - 1) * 1000) / ((1 << 14) - 1));
continue;
if (f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax) {
spin_lock_irqsave(&subs->lock, flags);
subs->freqm = f;
spin_unlock_irqrestore(&subs->lock, flags);
}
#endif
spin_lock_irqsave(&subs->lock, flags);
subs->freqm = f;
spin_unlock_irqrestore(&subs->lock, flags);
}
return 0;
@ -484,9 +478,11 @@ static int retire_playback_sync_urb_hs(snd_usb_substream_t *subs,
if (urb->iso_frame_desc[0].status == 0 &&
urb->iso_frame_desc[0].actual_length == 4) {
f = combine_quad((u8*)urb->transfer_buffer) & 0x0fffffff;
spin_lock_irqsave(&subs->lock, flags);
subs->freqm = f;
spin_unlock_irqrestore(&subs->lock, flags);
if (f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax) {
spin_lock_irqsave(&subs->lock, flags);
subs->freqm = f;
spin_unlock_irqrestore(&subs->lock, flags);
}
}
return 0;