Date: Wed, 9 Nov 2016 07:09:27 +0000 (UTC) From: Hans Petter Selasky <hselasky@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r308461 - head/sys/dev/sound/usb Message-ID: <201611090709.uA979RAZ035472@repo.freebsd.org>
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Author: hselasky Date: Wed Nov 9 07:09:27 2016 New Revision: 308461 URL: https://svnweb.freebsd.org/changeset/base/308461 Log: Allow higher sample rates to have more jitter than lower ones. PR: 208791 MFC after: 3 days Modified: head/sys/dev/sound/usb/uaudio.c Modified: head/sys/dev/sound/usb/uaudio.c ============================================================================== --- head/sys/dev/sound/usb/uaudio.c Wed Nov 9 06:47:29 2016 (r308460) +++ head/sys/dev/sound/usb/uaudio.c Wed Nov 9 07:09:27 2016 (r308461) @@ -2079,6 +2079,8 @@ uaudio_chan_play_sync_callback(struct us * recording channel: */ if (ch->priv_sc->sc_rec_chan.num_alt == 0) { + int32_t jitter_max = howmany(sample_rate, 16000); + /* * Range check the jitter values to avoid * bogus sample rate adjustments. The expected @@ -2087,12 +2089,11 @@ uaudio_chan_play_sync_callback(struct us * mandates this requirement. Refer to chapter * 5.12.4.2 about feedback. */ - if (temp > sample_rate) - ch->jitter_curr = 1; - else if (temp < sample_rate) - ch->jitter_curr = -1; - else - ch->jitter_curr = 0; + ch->jitter_curr = temp - sample_rate; + if (ch->jitter_curr > jitter_max) + ch->jitter_curr = jitter_max; + else if (ch->jitter_curr < -jitter_max) + ch->jitter_curr = -jitter_max; } ch->feedback_rate = temp; break;
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