From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felix Homann Subject: Re: @Daniel Mack: Send you a FTU Date: Tue, 14 Jun 2011 13:37:53 +0200 Message-ID: <4DF74811.2080409@showlabor.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from vwp5738.webpack.hosteurope.de (vwp5738.webpack.hosteurope.de [83.169.30.203]) by alsa0.perex.cz (Postfix) with ESMTP id 4D5FC243FE for ; Tue, 14 Jun 2011 13:37:56 +0200 (CEST) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Daniel Mack Cc: =?ISO-8859-1?Q?Aur=E9lien_Leblond?= , alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org Hi Daniel, (just to have it public on the list) Am 14.06.2011 10:56, schrieb Daniel Mack: > > Quite frankly, I'm not fully aware about known issues with these > devices that need attention. Could you summarize which problems are > left to look at? > Here's a list of the issues I'm aware of: 1. Playback clicks: There are periodic clicks in the playback at all sample rates. They are not very noticable in normal use but when you playback a plain sine the clicks are very obvious. When we discussed it last year we suspected that the device uses "implicit feedback". For the record: When we used the device with QUIRK_AUDIO_STANDARD_INTERFACE quirks we had clickless playback at 48 kHz and 96 kHz, but playback at 44.1 kHz and 88.2 kHz was totally distorted and the kernel would eventually crash after a minute or so. 2. External clock sync The FTU devices are capable of syncing to an external clock via SPDIF. I don't know how to switch between internal and external clock. I don't even have a second audio interface to test with. 3. Mixer control steps: The mixer controls are working fine now but are very fine grained. Being that fine grained it is hard to control the mixer in some mixer programs like alsamixer (alsamixer-qt4 and gamix work fine). A little bit of fine tuning would be nice. But I don't know which step size the hardware actually supports. 4. Reverb unit: The FTU devices have a reverb unit which isn't supported, yet. It's straight forward based on the basic mixer support . I've almost got it wroking except for the "Reverb Program" switch. I know how to do it, so probably there will be a patch soon. 5. "Lost" URBs: Some users reported occasional playback distortion combined with dmesg output like this: "ALSA urb.c:480: frame 5 active: -18". I don't know if this is really related to the driver. Actually I don't think so but who knows ... Are there any other issues? Kind regards, Felix