From owner-freebsd-current@FreeBSD.ORG Wed Sep 19 06:02:21 2012 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EEAED1065672; Wed, 19 Sep 2012 06:02:21 +0000 (UTC) (envelope-from yanegomi@gmail.com) Received: from mail-ob0-f182.google.com (mail-ob0-f182.google.com [209.85.214.182]) by mx1.freebsd.org (Postfix) with ESMTP id 9F53C8FC0C; Wed, 19 Sep 2012 06:02:21 +0000 (UTC) Received: by obbun3 with SMTP id un3so888556obb.13 for ; Tue, 18 Sep 2012 23:02:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=oY+WkOiLveTeO5Ss6NaYsSptBIy05BzWzRIrVIvTwHA=; b=JYIuL3fCBKnsv6EN9sOLek0hvLICRJT8UqOvyaLQBDENdgHlxiRb8dt3nPdG1d/uNP 00Mzi9QZSVQwAaIpdz/g7WQKdI2xBJXWcQNLF0NgAqca/3t743ZKlRsHouYrpXPeE+V7 nV6T2bYaA+HdA100Fgxl1tElWWECGZWnlQHWcfo/oCxumh5ILr7UzcfGNNvJx3JcPDjc 1E18T/jIgP9u91Qh/bmSOV55LhXOpMfQG1MoZDkfsIzthJuROcVlp4eax5xWZvz/s40N n9lYRYS7Uy6eIzV31x2X9X7+mrV0uBK/lMDUwO/S+ZBEBNYQPJJiG+8u1YGyIzvGLp5S YECA== MIME-Version: 1.0 Received: by 10.60.20.69 with SMTP id l5mr2087467oee.114.1348034540566; Tue, 18 Sep 2012 23:02:20 -0700 (PDT) Received: by 10.76.142.201 with HTTP; Tue, 18 Sep 2012 23:02:20 -0700 (PDT) In-Reply-To: <50595E93.9080908@gmail.com> References: <5059194F.4090002@FreeBSD.org> <50595E93.9080908@gmail.com> Date: Tue, 18 Sep 2012 23:02:20 -0700 Message-ID: From: Garrett Cooper To: matt Content-Type: text/plain; charset=ISO-8859-1 Cc: Doug Barton , 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: Wed, 19 Sep 2012 06:02:22 -0000 On Tue, Sep 18, 2012 at 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. My guess would be that there is > an input that is defined and active in software, but is a loose, ungrounded > pin in real life. Like a second microphone input on the chip, but not > actually connected, would be my guess. Can you try purging out nids that you > don't use with loader tunables (set their as to 0)? Or sysctls as reboots > aren't as necessary anymore with snd_hda? Maybe something changed in > software that is seeing inputs that were not present. Also just try muting > all inputs with mixer... > > Just a guess, but when I hear squealing/whistling/howling I think "analog" > before I think "digital"... Could also be a bitmasking/32-bit vs 64-bit bug like what was fixed last year in snd_emu10kx. HTH! -Garrett