From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jonathan Woithe <jwoithe@just42.net>
Subject: Re: [FFADO-devel] [RFC][PATCH 0/3] ALSA: fireface: new
 driver for RME Fireface series (MIDI only)
Date: Mon, 7 Dec 2015 08:27:44 +1030
Message-ID: <20151206215744.GA6103@marvin.atrad.com.au>
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To: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Cc: tiwai@suse.de, alsa-devel@alsa-project.org, clemens@ladisch.de, ffado-devel@lists.sf.net
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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).

> 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.

jonathan