From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Sakamoto Subject: Re: [RFC][PATCH 0/3] ALSA: fireface: new driver for RME Fireface series (MIDI only) Date: Mon, 7 Dec 2015 10:27:08 +0900 Message-ID: <5664E06C.9080705@sakamocchi.jp> References: <1449408224-13955-1-git-send-email-o-takashi@sakamocchi.jp> <20151206215744.GA6103@marvin.atrad.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from smtp302.phy.lolipop.jp (smtp302.phy.lolipop.jp [210.157.22.85]) by alsa0.perex.cz (Postfix) with ESMTP id B9EA3265005 for ; Mon, 7 Dec 2015 02:27:11 +0100 (CET) In-Reply-To: <20151206215744.GA6103@marvin.atrad.com.au> 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: Jonathan Woithe Cc: tiwai@suse.de, alsa-devel@alsa-project.org, clemens@ladisch.de, ffado-devel@lists.sf.net List-Id: alsa-devel@alsa-project.org Hi, On Dec 07 2015 06:57, Jonathan Woithe wrote: > On Sun, Dec 06, 2015 at 10:23:41PM +0900, Takashi Sakamoto wrote: >> Unfortunately, ffado library can disturb this functionality. >> In RME::Device::init_hardware() function, the library sends a write transaction >> to 0x0000801003f4 with invalid value as higher part of address in IEEE 1212 or >> ISO/IEC 13213. This is a worst case I describe in patch 03. > > The number which FFADO writes to this register is not invalid: it is in fact > the same number which is used in drivers on other operating systems > (obtained from protocol analysis). No. As long as I tested with a debug option to firewire-ohci module, it sends write transaction with '01000000'. This value includes invalid node ID. ConfigRom::getNodeId() returns the invalid value. I think there's something wrong coding, such like forgetting initialization or update of the instance. >> I think it better that FFADO developers fixes the bug as long as they doesn't >> support MIDI functionality. > > As above, this is not exactly a bug because other systems set that register > to the value which FFADO uses. In the interests of interoperability I'm > willing to remove manipulation of this register from FFADO, but I suggest > that in time the ALSA driver should consider setting this register as is > done under other systems or else we could introduce subtle behavioural > differences down the track - at least until such time as we understand what > the high part of that register does. Regards Takashi Sakamoto