From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clemens Ladisch Subject: Re: Some information about UsbPre2 UAC2 support Date: Mon, 28 Jan 2013 15:17:01 +0100 Message-ID: <5106885D.4050508@ladisch.de> References: <1565248075.1826245.1359380896039.JavaMail.root@spooler2-g27.priv.proxad.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from out5-smtp.messagingengine.com (out5-smtp.messagingengine.com [66.111.4.29]) by alsa0.perex.cz (Postfix) with ESMTP id 3D2DA265220 for ; Mon, 28 Jan 2013 15:17:04 +0100 (CET) Received: from compute4.internal (compute4.nyi.mail.srv.osa [10.202.2.44]) by gateway1.nyi.mail.srv.osa (Postfix) with ESMTP id A460120CF9 for ; Mon, 28 Jan 2013 09:17:03 -0500 (EST) Received: from [10.1.2.65] (unknown [94.101.37.4]) by mail.messagingengine.com (Postfix) with ESMTPA id EFEBE8E08AE for ; Mon, 28 Jan 2013 09:17:02 -0500 (EST) In-Reply-To: <1565248075.1826245.1359380896039.JavaMail.root@spooler2-g27.priv.proxad.net> 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: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org shal@free.fr wrote: >>> I have to plug/unplug the sound card in order to have 2 configurations >>> descriptor for this device. >> >> That's strange; the get_descriptor request should be the same. > > - I used a standard kernel (with 64 as get_descriptor buffer size) > ... > - I reboot with modified kernel (with 65 as get_descriptor buffer size) > ... > - Now the sound card provides a UAC1+UAC2 configuration So the modified get_descriptor is stil necessary. > - I performed a usb_reset() > - I performed a get_descriptor using a usb_control() with 65 as buffer size The USB core will already issue the get_descriptor request before the driver gets informed that the device is there, so this won't help. Regards, Clemens