Date: Fri, 9 Jun 2000 14:45:58 -0500 From: "Richard Seaman, Jr." <dick@tar.com> To: Brian Somers <brian@Awfulhak.org> Cc: Maxim Sobolev <sobomax@FreeBSD.org>, Kenneth Wayne Culver <culverk@wam.umd.edu>, Chris Piazza <cpiazza@jaxon.net>, Cameron Grant <cg@FreeBSD.org>, cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org, brian@hak.lan.Awfulhak.org Subject: Re: cvs commit: src/sys/dev/sound/pcm channel.c Message-ID: <20000609144558.B566@tar.com> In-Reply-To: <20000609141129.A566@tar.com>; from dick@tar.com on Fri, Jun 09, 2000 at 02:11:29PM -0500 References: <dick@tar.com> <200006091630.RAA01120@hak.lan.Awfulhak.org> <20000609141129.A566@tar.com>
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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. -- Richard Seaman, Jr. email: dick@tar.com 5182 N. Maple Lane phone: 262-367-5450 Nashotah WI 53058 fax: 262-367-5852 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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