From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <486CEF87.6060504@domain.hid> Date: Thu, 03 Jul 2008 17:25:59 +0200 From: Gilles Chanteperdrix MIME-Version: 1.0 References: <486CE4C5.8050309@domain.hid> In-Reply-To: <486CE4C5.8050309@domain.hid> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] How can I make Xenomai share a mii bus with the kernel? List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Michael Galea Cc: xenomai@xenomai.org Michael Galea wrote: > I wonder if someone can suggest an approach to the following problem. > > We need to use xenomai to manage devices on the mii bus. The mii bus > has PHYs managed by linux. What is the best way of providing access to > both linux and xenomai? > > I know that before xenomai "loads", I can simply access the mii bus from > linux. But after xenomai loads, is the right answer to make the linux > function that reads the phy migrate into the xenomai domain and contend > for the bus there? What protects this access to the bus, is this a mutex or a spinlock ? If a spinlock, then simply make it an ipipe_spinlock, it will provide mutual exclusion between all domains. I do not think it can be a mutex anyway, since it may certainly possible for a driver to have a function that reads the mii status in a timer handler to maintain the IFF_RUNNING bit state of the ethernet interface. -- Gilles.