Nuttx does not support nested iteruups. In fact if you enable prioritization, you will get random crashes due to the reentrace to the common isr.
On Sun, Oct 25, 2020, 1:52 PM Matias N. <mat...@imap.cc> wrote: > Hi, > while working on nRF52 BLE link-layer I experienced some problems due to > delayed ISRs. This can be quite problematic > for handling all the tight timings required by the standard. I eventually > reached an implementation that can deal with this relatively well (BLE > standard gives some leeway for some small number of dropped packets and > also retransmits missing ones). However, as other peripherals start > generating more interrupts, this could actually become a problem. Also, I > think it would be good to know BLE ISRs will always have priority. > > I've been looking into how ISRs can be prioritized but I don't have much > experience with this, so I have some questions: > * Does nRF52 need explicit support for handling interrupts with different > priorities or is the support supposed to be taken care of at the ARM level > code? > * How well supported is this in nRF52/ARM? > * Do interrupt priorities imply nested interrupts? It isn't clear to me if > priorities only mean which ISR will get served first when they are pending > together or if it also implies that a low priority interrupt can be > interrupted to handle a higher priority one (I believe the latter is what > is usually refered to as "nested interrupts") > * How does enter_critical_section() deal with priorities? How do I know > which priority is masked and which one isn't? > * Which configs should I enable to try this? > > Thanks, > Matias
