Date: Fri, 09 Jun 2000 13:14:58 -0700 From: Matthew Reimer <mreimer@vpop.net> To: "Richard Seaman, Jr." <dick@tar.com>, cvs-all@freebsd.org Subject: Re: cvs commit: src/sys/dev/sound/pcm channel.c Message-ID: <39415042.10495F90@vpop.net> References: <lists.freebsd.cvs-all.20000609141129.A566@tar.com> <lists.freebsd.cvs-all.20000609144558.B566@tar.com>
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"Richard Seaman, Jr." wrote: > > On Fri, Jun 09, 2000 at 02:11:29PM -0500, Richard Seaman, Jr. wrote: > > > > If I just cat a .au file into /dev/audio, I get about 1/4 of a second > > > of plan and then silence, with & without the patch. > > > > Your symptoms are different then. Don't know if the cause is the > > same. > > Thinking about this some more, and as a followup to my last message, here's > what I'm guessing is happening to you. > > You fill the device buffers very rapidly. Since chn_wrintr is not getting > called as dma activity occurs, the only time the dma pointers can get updated > and therefore indicate that the buffers aren't full is when you write to > the buffers -- but you can't because they're already marked full. ie. > you're deadlocked. The sound you hear is the dma buffers emptying, but your > app never knows it happened because the buffers are still marked full. > > My case is the opposite side of the problem. My app doesn't always fill the > buffers fast enough, and the dma pointers get corruped. > > I'd guess that those that don't have problems either a) are getting > dma interrupts, or b) manage to fill the buffers at a rate that is > neither too fast nor too slow. That explanation fits my experience with recording (CS4236/4237B). Recording kind of works at 11025 and 22050 samples per second, but not with 8000 or 44100 (just get a short blip of noise). I say "kind of" because the recording that seems to work is somewhat truncated, where the last few seconds are missing. Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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