> >-----Original Message----- >From: Xenomai <[email protected]> On Behalf Of François Legal via >Xenomai >Sent: Wednesday, June 16, 2021 3:16 PM >To: [email protected] >Subject: Large gpio interrupt latency > >Hello, > >working on a realtime data recorder (for which I submitted a patch to add >timestamp retrieval for net packets), I experience a strange latency problem >with taking GPIO interrupts. > >So basically my app monitors network packets (which as received by the DUT >would trigger toggling of a GPIO on the DUT) and one GPIO. >We know (from some ohter reference instrument) that the DUT would toggle the >GPIO 1-2ms after receiving a specific network packet. > >My recorder app relies on the timestamping of events done in interrupts >service routines for GPIOs and network interface. By checking the timestamps >returned by the application, I get an about 50ms delay between the network >packet and the GPIO (so something between 51 and 52ms delay). >
Are you toggling gpio and access gpio device through your rtdm device like on path /dev/rtdm/your_gpiocontroller/gpio*? Hongzhan Chen >I wonder where that might be coming from. > >Any idea ? > >thanks in advance > >François
