From owner-freebsd-multimedia@FreeBSD.ORG Mon Jan 2 15:41:23 2012 Return-Path: Delivered-To: freebsd-multimedia@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DBA17106564A for ; Mon, 2 Jan 2012 15:41:23 +0000 (UTC) (envelope-from clemens@ladisch.de) Received: from out5.smtp.messagingengine.com (out5.smtp.messagingengine.com [66.111.4.29]) by mx1.freebsd.org (Postfix) with ESMTP id A62F28FC14 for ; Mon, 2 Jan 2012 15:41:23 +0000 (UTC) Received: from compute4.internal (compute4.nyi.mail.srv.osa [10.202.2.44]) by gateway1.nyi.mail.srv.osa (Postfix) with ESMTP id 6EDD121076 for ; Mon, 2 Jan 2012 10:25:48 -0500 (EST) Received: from frontend1.nyi.mail.srv.osa ([10.202.2.160]) by compute4.internal (MEProxy); Mon, 02 Jan 2012 10:25:48 -0500 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=message-id:date:from:mime-version:to:cc :subject:references:in-reply-to:content-type :content-transfer-encoding; s=smtpout; bh=W77PaQmwlroQRSztZ/baJF 9PGjQ=; b=KDiTaVzksN+GVg2/ECKopw+5aoFaUvEkFPis15nuyHFQH2gX54zUcY EFxp6y7nzdsS18sYaucj80cpm5ivH78TYOtErNUf+eh2F8dBNCvmYagv4LAD3W/T C/7vQ1nbm9hgDVBnBxRyZ+aHbzcIjW6IxbVa0HSRX+c1ndDf/Zqew= X-Sasl-enc: Kn+9CLSnMb4sNY07e0vNy8A1Jzo3PASScGT+R+uaIKgV 1325517947 Received: from [192.168.42.121] (unknown [46.115.1.25]) by mail.messagingengine.com (Postfix) with ESMTPSA id 2315E8E0128; Mon, 2 Jan 2012 10:25:46 -0500 (EST) Message-ID: <4F01CC65.2070408@ladisch.de> Date: Mon, 02 Jan 2012 16:25:25 +0100 From: Clemens Ladisch User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.15) Gecko/20110323 Thunderbird/3.1.9 MIME-Version: 1.0 To: Hans Petter Selasky References: <1325263531.4997.4.camel@localhost> <201112301859.32280.hselasky@c2i.net> <1325271329.3649.6.camel@localhost> <201112302241.55813.hselasky@c2i.net> In-Reply-To: <201112302241.55813.hselasky@c2i.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: freebsd-multimedia@freebsd.org Subject: Re: M-Audio Oxygen 49: snd_uaudio cycles (loads, detaches, loads.... ad infinitum) X-BeenThere: freebsd-multimedia@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Multimedia discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 02 Jan 2012 15:41:23 -0000 Hans Petter Selasky wrote: > It looks like your device has a problem with the clear-stall of the BULK > endpoint used for MIDI. In other words it is not fully USB compliant. After devices whose descriptors were so broken that they couldn't ever run with newer Windows versions, after devices where (only!) the capture interface used big-endian samples, and after devices that corrupted their data buffer when receiving MIDI data with running status, I'm *extremely* surprised that there would be another M-Audio device with firmware bugs. > I'm not sure how we can avoid this. Plain MIDI does not have any error detection, so there is no error condition that could be reported with a stall. I've never seen a stalled MIDI endpoint, except for devices with broken hardware where the endpoint was stalled from the beginning and where a clear-stall wouldn't help. The Linux driver neither detects nor clears stalls, and works fine. It's obvious that clear-stall requests are not well tested in MIDI devices' firmwares, so I wouldn't be surprised if there were other devices that have the same bug, or even lock up. Is there a reason that umidi_probe/_open unconditionally issue clear- stalls, other than "just to be safe"? Regards, Clemens