From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Richter Subject: Re: [PATCH 39/39] bebob: Add support for M-Audio special Firewire series Date: Sat, 1 Mar 2014 11:53:40 +0100 Message-ID: <20140301115340.589ab770@stein> References: <1393558072-25926-1-git-send-email-o-takashi@sakamocchi.jp> <1393558072-25926-40-git-send-email-o-takashi@sakamocchi.jp> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from einhorn.in-berlin.de (einhorn.in-berlin.de [192.109.42.8]) by alsa0.perex.cz (Postfix) with ESMTP id 5228A2652F1 for ; Sat, 1 Mar 2014 11:53:43 +0100 (CET) In-Reply-To: <1393558072-25926-40-git-send-email-o-takashi@sakamocchi.jp> 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: Takashi Sakamoto Cc: tiwai@suse.de, alsa-devel@alsa-project.org, clemens@ladisch.de, ffado-devel@lists.sf.net List-Id: alsa-devel@alsa-project.org On Feb 28 Takashi Sakamoto wrote: > This commit allows this driver to support some models which M-Audio produces > with DM1000 but its firmware is special. They are: > - Firewire 1814 > - ProjectMix I/O [...] > M-Audio special firmware quirks: [...] > - They often handle requests without responding. In this reason, this driver > often fail to handle them correctly. [...] > An fallback at timeout in the operations for CMP was already > added by previous commit. But for isochronous resource management, no fallbacks > are added. Further works are needed for Linux Firewire Subsystem. We could add a workaround in drivers/firewire/core-iso.c which works similar to your CMP related workaround in patch 18/39. I.e., after a timed-out lock request to CHANNELS_AVAILABLE or BANDWIDTH_AVAILABLE, perform a read request to see what happened. Like your CMP workaround, this is fragile because it races with concurrent lock requests. Or we could add a workaround in drivers/firewire/core-card.c which would attempt to make the local node root node (and thereby IRM) if it detects that an M-Audio device is currently IRM. Not sure what's better. -- Stefan Richter -=====-====- --== ----= http://arcgraph.de/sr/