From 50cdbf1519a891bec4ce306c7bae397a0d8e7246 Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Fri, 13 May 2005 07:44:13 +0200 Subject: [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 --- sound/usb/usbaudio.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) (limited to 'sound/usb') diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c index c360ab9783d..a6ed0d08337 100644 --- a/sound/usb/usbaudio.c +++ b/sound/usb/usbaudio.c @@ -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; -- cgit v1.2.3