From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <5336CC15.8070102@xenomai.org> Date: Sat, 29 Mar 2014 14:35:17 +0100 From: Gilles Chanteperdrix MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Subject: Re: [Xenomai] IRQ Handler latency List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: xenomai@xenomai.org Le 29/03/2014 00:41, Newell Jensen a écrit : > Hello, > > I have successfully created an RTDM driver that uses the EPIT timer on the > i.mx6dl-sabresd board. The reason I created this driver is I wanted to see > what the hard interrupt latency is using Xenomai. > > AFAIK, I am using the RTDM skin in the proper way. However, I wanted to > run my code by the experts (you guys), to see if there is any improvements > that I can make. > > Here is a link to my code: http://pastebin.com/TFWLq9mq Also, the code measuring latency seems all wrong. Debugging this looks like a waste of time: - we provide the latency test, which we hope is reasonably debugged, so duplicating the effort is a waste of (our) time; - from the code, I would guess the EPIT runs at 6 MHz, whereas the cortex A9 has timers running at 400 or 500 MHz, which results in lower latencies for accessing their registers. -- Gilles.