Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757320AbYFLVuo (ORCPT ); Thu, 12 Jun 2008 17:50:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752880AbYFLVuf (ORCPT ); Thu, 12 Jun 2008 17:50:35 -0400 Received: from rv-out-0506.google.com ([209.85.198.239]:36044 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752246AbYFLVue (ORCPT ); Thu, 12 Jun 2008 17:50:34 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=FN+yEfPpdpr1TgjuCjIFkoSYuaY+r/rKhEJ1zKWMx0uXM1fQgTPgBW9VPWOo2/8pXM e7ceXRIVQ+ye27+WgW50CevDvgjwHFvalyRXuIOoIc+x9R9yHr4kMj4aV8YRb99g5faQ OMwOriEsOraaY/xdE1SZJmuOJrj06WNI+tJHQ= Message-ID: <6278d2220806121450h39280637udbe06ffb92fbb0d1@mail.gmail.com> Date: Thu, 12 Jun 2008 22:50:32 +0100 From: "Daniel J Blueman" To: "Takashi Iwai" Subject: Re: ALC883 recording troubles... Cc: "Linux Kernel" , "Vegard Nossum" In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <6278d2220806091259t47c9b070v269da0f5855ef014@mail.gmail.com> <6278d2220806111200g4f802885wfc5f0fd6c0405efb@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3367 Lines: 85 On Thu, Jun 12, 2008 at 11:49 AM, Takashi Iwai wrote: > At Wed, 11 Jun 2008 20:00:17 +0100, > Daniel J Blueman wrote: >> >> On Tue, Jun 10, 2008 at 6:59 AM, Takashi Iwai wrote: >> > At Mon, 9 Jun 2008 20:59:00 +0100, >> > Daniel J Blueman wrote: >> >> >> >> Hi Takashi-san, >> >> >> >> I'm experiencing DC offset with the microphone on 2.6.24 (Ubuntu 8.04 >> >> LTS x86-64). I can see on Audacity that the DC offset that varies with >> >> the recording capture level. >> > >> > Could you elaborate? The mic bias level could be changed via the pin >> > control value. Usually, it's set as VREF 80%. >> >> When the recording->capture level is set to 0, the mic has no DC >> offset as expected. Maxing the recording->capture level, the mic input >> is saturated, in between, we see a linear connection. >> >> >> Plus, the mixer playback->mic-boost >> >> muting enables/disables mic-boost in recording. >> > >> > This is a known bug in alsa-lib mixer abstraction. No kernel issue. >> >> >> It feels like the ALC883 pins aren't configured quite right. The mobo >> >> is an Asus P5E-VM with current BIOS [1] >> >> >> >> What's the routine to debug this? Would it help to install windows, >> >> dump the register space and compare? >> > >> > You can find *.INI file that contains the default pin configuration >> > in Windows. This might be useful in the case BIOS is broken but >> > Windows does a black magic. >> >> That'll be these defaults stashed in the INF file [2]. Let me know if >> it's not what you expected and I'll publish the complete INF file. >> >> > Anyway, please run alsa-info.sh with --no-upload option and show the >> > generated file here. It contains the codec information and mixer >> > setup. >> > http://hg.alsa-project.org/alsa/raw-file/tip/alsa-info.sh >> >> See [3]. >> >> > Also, you can adjust the pin setting on the fly via hda-verb utility >> > below: >> > http://ftp.suse.com/pub/people/tiwai/misc/hda-verb-0.2.tar.bz2 >> > >> > Don't forget to build snd-hda-intel module with >> > CONFIG_SND_HDA_HWDEP=y to use this command. >> >> I'll give this a shot if I get time. > > You can try to adjust VREF value of mic pins. > For example, the node 0x18 and 0x19 correspond to the rear and front > mics, respectively. Then run the following as root: > > # ./hda-verb /dev/snd/hwC0D0 0x18 SET_PIN_WID 0x21 > > which will change the widget 0x18 (rear mic) to input-VREF 50% > (0x21). The original value is input-VREF 80% (0x24). Yes, I had tried this and it does not help, perhaps only changing the magnitude of the sampled mic input. Another smoking gun, is when changing certain mixer settings (both on gnome-mixer and alsamixer), eg playback->front mic amplitude, moving the slider up and down, the L/R linking seems to be almost randomly unlinked and the other L/R channel jumps to a different value. When re-linking the L/R channels, often, it'll unlink again and change both value after reading back the change; mute can be erratic too. Confirmed with 2.6.26-r5. Is there a good way to debug this also? > Takashi -- Daniel J Blueman -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/