From owner-freebsd-current@FreeBSD.ORG Mon Oct 1 06:54:59 2012 Return-Path: Delivered-To: freebsd-current@FreeBSD.org Received: from mx2.freebsd.org (mx2.freebsd.org [69.147.83.53]) by hub.freebsd.org (Postfix) with ESMTP id 03FDD106568F for ; Mon, 1 Oct 2012 06:54:59 +0000 (UTC) (envelope-from dougb@FreeBSD.org) Received: from opti.dougb.net (hub.freebsd.org [IPv6:2001:4f8:fff6::36]) by mx2.freebsd.org (Postfix) with ESMTP id 9271814D840; Mon, 1 Oct 2012 06:54:30 +0000 (UTC) Message-ID: <50693E26.4020207@FreeBSD.org> Date: Sun, 30 Sep 2012 23:54:30 -0700 From: Doug Barton Organization: http://SupersetSolutions.com/ User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:15.0) Gecko/20120911 Thunderbird/15.0.1 MIME-Version: 1.0 To: matt References: <5059194F.4090002@FreeBSD.org> <50595E93.9080908@gmail.com> <50595F83.9030008@FreeBSD.org> <5059636B.4020902@gmail.com> In-Reply-To: <5059636B.4020902@gmail.com> X-Enigmail-Version: 1.4.4 OpenPGP: id=1A1ABC84 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-current@FreeBSD.org Subject: Re: squealing/whistling audio X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 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: Mon, 01 Oct 2012 06:54:59 -0000 On 09/18/2012 23:17, matt wrote: > On 09/18/12 23:00, Doug Barton wrote: >> On 9/18/2012 10:56 PM, matt wrote: >>> On 09/18/12 18:01, Doug Barton wrote: >>>> Sometime in the last couple of months an old problem has resurfaced on >>>> HEAD, a sort of squealing/whistling sound in the audio, even without >>>> anything playing. The sound is similar to the wind whistling through >>>> something. >>>> >>>> Before I blindly go off on a bisecting spree, does anyone have a >>>> suggestion as to where I might look? >>>> >>>> Doug >>>> >>>> >>> Electrically that's usually oscillation (too high gain or too much >>> electrical feedback) or an unshielded input. >> Sorry, I should have been more clear. This problem doesn't occur in >> windows, or linux, and last time I checked, didn't occur in freebsd 8. I >> have everything irrlevant zeroed out in mixer. >> >> Doug >> > It was worth a shot. It is possible that each OS (and version) is > setting the associations up properly though except HEAD on your machine. > Is it a laptop or a desktop board? Desktop. > Any difference in the nid configuration between freebsd 8 and HEAD? No. > Does changing any of the hw.snd sysctls (latency, exact rate, vpc_0db) > have any effect on the sound? It doesn't affect the squeal. > http://freshbsd.org/commit/freebsd/r230551 might be worth a look. Didn't help. > I > couldn't find anything newer that looked like it would have an effect. > Their are some earlier commits around January that are dealing with > signal gain that could also have an effect. > > Otherwise, I'm not sure where else to look. Thanks anyway. Doug -- I am only one, but I am one. I cannot do everything, but I can do something. And I will not let what I cannot do interfere with what I can do. -- Edward Everett Hale, (1822 - 1909)