From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 1 Dec 2014 19:54:21 +0100 From: Gilles Chanteperdrix Message-ID: <20141201185421.GD28038@hermes> References: <314E5ECDAA86314791309FA670550F89C9C4FD8A@SINTEFEXMBX05.sintef.no> <20141201073433.GR2964@hermes> <314E5ECDAA86314791309FA670550F89C9C5006D@SINTEFEXMBX05.sintef.no> <20141201085028.GA21004@hermes> <314E5ECDAA86314791309FA670550F89C9C50321@SINTEFEXMBX05.sintef.no> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Xenomai] WARNING: at arch/arm/kernel/ipipe.c:157 ipipe_set_irq_affinity+0x47/0x70() List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Hidde Verstoep Cc: "xenomai@xenomai.org" On Mon, Dec 01, 2014 at 12:35:18PM +0100, Hidde Verstoep wrote: > > By the way.. When compiling kernel for Xenomai, I am advised to > > turn off CPU Frequency scaling "as it is known to cause > > trouble". When enabled I could inspect and set the CPU clock > > frequency by the "cpufreq-info" and "cpufreq-set". These tools > > are no longer available and I don't find any settings in the > > menuconfig. > > > > What is the default BBB CPU frequency when frequency scaling is turned off? > > From my experience with the BBB and Xenomai: > The default CPU frequency with frequency scaling turned off is 600 > MHz. This was not acceptable for me since the BBB supports 1000 > Mhz. Well, to what frequency does u-boot set the processor? Because if u-boot sets the frequency to 600 MHz and Linux does not change it, chances are that if you set the frequency to 1 GHz in u-boot, Linux will not change it either. This is what I do on the omap3 board I use: set the frequency to 720 MHz in u-boot. -- Gilles.