From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre Ossman Subject: [RFE] Power down AC'97 when muted Date: Wed, 22 Dec 2004 20:41:23 +0100 Message-ID: <41C9CDE3.4020605@drzeus.cx> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: alsa-devel-admin@lists.sourceforge.net Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org I have a request for a new feature in the AC97 driver (my card is an intel ICH4). I'd like to see the driver power off the AC97 part when the master volume is muted. Currently the power control has a seperate volume control that can be used. The reason I want this is because my laptop has a LED indicating mute status. This is triggered by the power down function of the AC97 function. Since the power is exposed through a volume control this could be done in user space, but that would me that every program that mutes the sound card would need special logic to see if the card has an "External amplifier" (as the channel is called). Therefore it seems much better to do this in the driver. Another point is that Windows seems to have this behaviour (since the LED functions fine there in every application) so manufacturers rely on this (HP in my case). I tried doing this myself by adding an extra call inside ac97_put_double() checking for changes to the master channel but I couldn't get it to work. I just got a faint flicker out of the LED. If people give me enough pointers I might be able to put together a patch for this. Rgds Pierre ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/