From owner-freebsd-current@FreeBSD.ORG Wed Dec 17 14:04:51 2003 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id CCFD416A4CF for ; Wed, 17 Dec 2003 14:04:51 -0800 (PST) Received: from anduin.net (anduin.net [212.12.46.226]) by mx1.FreeBSD.org (Postfix) with SMTP id 3D8C943D39 for ; Wed, 17 Dec 2003 14:04:48 -0800 (PST) (envelope-from ltning@anduin.net) Received: (qmail 2057 invoked by uid 6759); 17 Dec 2003 22:04:47 -0000 Received: from ltning@anduin.net by anduin.net by uid 82 with qmail-scanner-1.20 (clamscan: 0.60. spamassassin: 2.60. Clear:RC:1(212.12.46.226):. Processed in 0.033043 secs); 17 Dec 2003 22:04:47 -0000 X-Qmail-Scanner-Mail-From: ltning@anduin.net via anduin.net X-Qmail-Scanner: 1.20 (Clear:RC:1(212.12.46.226):. Processed in 0.033043 secs) Received: from anduin.net (ltning@212.12.46.226) by anduin.net with SMTP; 17 Dec 2003 22:04:47 -0000 Message-ID: <3FE0D331.6050601@anduin.net> Date: Wed, 17 Dec 2003 23:05:37 +0100 From: Eirik Oeverby User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.6b) Gecko/20031212 Thunderbird/0.4 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Robert Watson , current@freebsd.org References: In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: Distorted sound on -CURRENT X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 17 Dec 2003 22:04:52 -0000 Robert Watson wrote: > Just to make sure: you're not running with WITNESS in your kernel, right? > That adds substantial overhead to every lock operation, and can really > impact interrupt latency. No, I'm not using WITNESS - doing so has no effect anyway (I tested). > Also, you might want to see if your sound device is sharing an interrupt > with another device that isn't marked MPSAFE, or sharing an interrupt at > all, which also substantially impacts interrupt latency. We're working on > pushing Giant out of various device drivers, but are only partway down > that road, which might well be the problem. What's a good way to check that, apart from going through dmesg? I'm gonna have to do that tomorrow, so tired I can't focus my eyes properly anymore ;) Thanks, /Eirik > > Robert N M Watson FreeBSD Core Team, TrustedBSD Projects > robert@fledge.watson.org Senior Research Scientist, McAfee Research > > On Wed, 17 Dec 2003, Eirik Oeverby wrote: > > >>Hi all, >> >>For a long time I have had problems with sound on my ThinkPad, which has >>a rather sucky Crystal chipset. The problems consist of skips and pops >>and crackles when playing back audio, and makes it hopeless to listen to >>any kind of music while working (or playing ;). >> >>There have been attempts at fixing this earlier, which has helped >>somewhat, but I always thought this was a problem on my chipset only - >>but this does not seem to be the case. >> >>I have now tested in a machine that has a SB Live! card (snd_emu10k1 >>module), and I'm experience the same problems, just even more pronounced >>than with the Crystal chipset. >> >>The interesting thing is - this is a non-issue in all 4.x versions of >>FreeBSD, and it's a non-issue in all other OSes I have tried on the >>respective computers. I am therefore led to believe there has been some >>kind of screwup with the PCM or chipset drivers in -CURRENT, or perhaps >>in some underlying code. This has been a problem atleast since >>5.1-RELEASE, and I do believe (but cannot confirm) it was a problem with >>5.0-RELEASE aswell. Choice of scheduler (SCHED_4BSD or SCHED_ULE) has no >>influence, neither has there been any difference before or after the >>i386 interrupt code switch. >> >>I home someone can have a look at this, it is of minor importance but >>major annoyance - and personally I think it should be (attempted) fixed >>before 5.2-RELEASE, if possible. It does make a bad impression on >>people, even in a FreeBSD-house such as the one I am working for right >>now. >> >>Best regards, >>Eirik Oeverby >> >>_______________________________________________ >>freebsd-current@freebsd.org mailing list >>http://lists.freebsd.org/mailman/listinfo/freebsd-current >>To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org" >> > >