On Sat, Sep 28, 2013 at 8:52 AM, Harry May <[email protected]> wrote: > I spent hours finding a bug in my GPIO kernel driver (blocking the system) > until I found the reason: > > While the system has to process a lot of data (interrupts), i.e. streaming > of music, video, or handling signals from a GPIO. > the kernel hangs showing an I2C controller timeout in the journal. > > This always happens when the CPU frequency is atomatically switched by the > cpu governor. > > I am using this commands to disable frequency switching: > > cpufreq-set -c 0 -g performance > cpufreq-set -d 1GHz > cpufreq-set -u 1GHz > > to check if it worked: cpufreq-info > > this must print the line: > current policy: frequency should be within 1000 MHz and 1000 MHz. > > If somebody knows a better way to disable thew cpu governor, please tell us. > > Is there any plan to solve the conflict between the cpu governor and the I2C > causing I2C contoller timeouts ? >
If you know beforehand that the system needs to start operating at 1GHz you could switch over to the userspace governor and then set the frequency. Using the userspace governor ensures that the frequency doesn't change automatically. This could in theory impact the average power consumption but can be used as a stopgap solution till you find out why the timeouts are happening in the first place. Regards, Vaibhav -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
