Hi > On Fri, Aug 18, 2017 at 8:35 AM, Cliff Brake <cliff.brake@xxxxxxxxx> wrote: > > I have an application where we need to tweak a PWM setting every 10uS. > > My impression is this is beyond the capabilities of linux+rt, but want > > to verify I'm not missing anything before we add an external > > microcontroller to handle this. > > > > I've run some experiments on a i.MX6UL with v4.1+rt, and observe > > delays of ~50us when toggling a GPIO in a Linux driver using a > > hrtimer. On Fri, Aug 18, 2017 at 10:34:19AM -0400, Cliff Brake wrote: > After a suggestion of using a NMI and a bit of research, it seems > something like the following article is the probably a reasonable > approach: > > http://free-electrons.com/blog/fiq-handlers-in-the-arm-linux-kernel/ If a PWM IP is present on the chip, won't updating the PWM compare registers within 10us (PWM @100KHz) achieve the required ?, toggling delay & jitter shouldn't be a worry here, right ? (assuming PWM compare registers can be updated every 10us using hrtimers) afzal -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
