From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: [PATCH] ALSA: hda - Implement loopback control switch for Realtek and other codecs Date: Thu, 10 Dec 2015 09:03:01 +0100 Message-ID: References: <1449591011-21360-1-git-send-email-tiwai@suse.de> Mime-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id C4E8F261721 for ; Thu, 10 Dec 2015 09:03:01 +0100 (CET) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Raymond Yau Cc: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org On Thu, 10 Dec 2015 08:07:23 +0100, Raymond Yau wrote: > > 2015-12-09 0:10 GMT+08:00 Takashi Iwai : > > > Many codecs, typically found on Realtek codecs, have the analog > > loopback path merged to the secondary input of the middle of the > > output paths. Currently, we don't offer the dynamic switching in such > > configuration but let each loopback path mute by itself. > > > > This should work well in theory, but in reality, we often see that > > such a dead loopback path causes some background noises even if all > > the elements get muted. Such a problem has been fixed by adding the > > quirk accordingly to disable aamix, and it's the right fix, per se. > > The only problem is that it's not so trivial to achieve it; user needs > > to pass a hint string via patch module option or sysfs. > > > > This patch gives a bit improvement on the situation: it adds "Loopback > > Mixing" control element for such codecs like other codecs (e.g. IDT or > > VIA codecs) with the individual loopback paths. User can turn on/off > > the loopback path simply via a mixer app. > > > > For keeping the compatibility, the loopback is still enabled on these > > codecs. But user can try to turn it off if experiencing a suspicious > > background or click noise on the fly, then build a static fixup later > > once after the problem is addressed. > > > > Other than the addition of the loopback enable/disablement control, > > there should be no changes. > > > > How about the amp in at those mixers of surround jacks / mio jacks ? An example? Takashi