From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Baumgart Subject: Re: MiniDSP USBStreamer / UAC2 / Alsamixer bogus Date: Sat, 24 May 2014 12:22:10 +0200 Message-ID: <538072D2.9020106@gmx.de> References: <537F82CD.6010907@zonque.org> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15"; Format="flowed" Content-Transfer-Encoding: quoted-printable Return-path: Received: from mout.gmx.net (mout.gmx.net [212.227.17.20]) by alsa0.perex.cz (Postfix) with ESMTP id E7429260864 for ; Sat, 24 May 2014 12:22:15 +0200 (CEST) In-Reply-To: <537F82CD.6010907@zonque.org> 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: Daniel Mack , alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org Hi Daniel, Thanks for the guidance! I don't have the unit at hand right now, but will give it a try next = week and see what I can find... All the best, Jan On 5/23/14 7:18 PM, Daniel Mack wrote: > Hi, > > On 05/22/2014 07:36 PM, Jan Baumgart wrote: >> AudioControl Interface Descriptor: >> bLength 16 >> bDescriptorType 36 >> bDescriptorSubtype 9 (EXTENSION_UNIT) >> Warning: Descriptor too short > > Hmm, lsusb is right here - bLength should be 16+p ... > >> bUnitID 51 >> wExtensionCode 0 >> bNrPins 1 > > ... where p is this value: 1. > >> baSourceID( 0) 2 >> bNrChannels 8 >> wChannelConfig 0 >> iChannelNames 3 >> bmControls 0x00 >> iExtension 42 > > Hence, the iExtension value is wrong, ... > >> AudioControl Interface Descriptor: >> bLength 42 > > because it actually is bLength of the next descriptor. So there's > definitely a problem in the USB descriptors, I'm just not sure how we > should deal with that. > > I'm also not entirely sure if that explains your control name trouble. > If you're interested in debugging this, have a look at the function > sound/usb/mixer.c, function build_audio_procunit(), especially the lower > half where we try to determine a nice name for the new control. You > could start dumping the variable 'nameid' and see what it contains. > > Also, this device reports strings to describe the channel names > (iChannelNames), which the driver currently doesn't care about. It might > be worth fetching them and see what they contain. On the other hand, > ALSA doesn't allow us to provide names for individual sub-controls (for > each of the 8 mixer values inside one control). > > Are you up for a little trial and error? I doubt that this will fix your > clock selector trouble though, but for that, the usbmon traces should > give a hint. > > > Best regards, > Daniel > -- = Jan Baumgart Technischer Mitarbeiter Hochschule f=FCr Musik und Darstellende Kunst Eschersheimer Landstr. 29-39 60322 Frankfurt am Main