Hi, Some more info on chained irq vs mux below that might help. * Tony Lindgren <tony@xxxxxxxxxxx> [190219 15:36]: > * Lokesh Vutla <lokeshvutla@xxxxxx> [190219 08:51]: > > With this can you tell me how can we not have a device-tree and still support > > irq allocation? > > Using standard dts reg property to differentiate the interrupt > router instances. And if the interrupt router is a mux, you should > treat it as a mux rather than a chained interrupt controller. > > We do have drivers/mux nowadays, not sure if it helps in this case > as at least timer interrupts need to be configured very early. Adding Linus Walleij to Cc since he posted a good test to consider if something should use chained (or nested) irq: "individual masking and ACKing bits and can all be used at the same time" [0] Not sure if we have that documented somewhere? But seems like the interrupt router should be set up as a separate mux driver talking with firmware that the interrupt controller driver calls on request_irq()? Cheers, Tony [0] https://marc.info/?l=linux-omap&m=155065629529311&w=2
