From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <486CF31B.2040100@domain.hid> Date: Thu, 03 Jul 2008 11:41:15 -0400 From: Michael Galea MIME-Version: 1.0 References: <486CE4C5.8050309@domain.hid> <486CEF87.6060504@domain.hid> In-Reply-To: <486CEF87.6060504@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: Gilles Chanteperdrix Cc: xenomai@xenomai.org Gilles Chanteperdrix wrote: > 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. > Thanks, access to the bus is provided by a spinlock in drivers/net/phy/phy.c, so I will try ipipe_spinlock (when I get hardware :-)). I assume that I can make it an ipipe_spinlock and use that from linux even before xenomai is loaded. Thanks