On Thu, May 4, 2023 at 7:11 AM Nathan Hartman <hartman.nat...@gmail.com> wrote:
> On Thu, May 4, 2023 at 5:46 AM Jernej Turnsek <jernej.turn...@gmail.com> > wrote: > >> I am developing a driver which is processing peripheral interrupts every >> 6.4 microseconds and every 16th interrupt calling notify function from HP >> work queue. But scheduling workqueue does lock interrupts (through >> critical >> section) up to 20us sometimes, causing my peripheral missing interrupts. >> The same thing occurs if calling the notify function with nxsem_post >> directly from ISR. DMA is not an option. I am working with the NXP RT1064 >> board. How can I wake the read function without locking interrupts? >> Thanks. >> > That chip is Arm Cortex M7. I think zero-latency interrupts are supported > on that. If so, you could try to use that to service the 6.4us interrupt. > > Zero-latency interrupts cannot use OS services because they exist outside > the OS. Therefore, to rendezvous with the hp queue, each 16th interrupt, > trigger an otherwise unused interrupt vector, which will be serviced by a > "normal" ISR, which can in turn hand off the data to the hp queue. > > There's a page about this somewhere... > I found it in the old wiki: https://cwiki.apache.org/confluence/display/NUTTX/High+Performance%2C+Zero+Latency+Interrupts I don't see it in the repo Documentation. This is an important thing that should be in the repo. Cheers Nathan
