Hello, I am trying to request DMA interrupts in real-time domain. When I request the irq with rtdm_irq_request(), the irq is successfully registered but at the first interrupt the system goes into a hard locked state. I tried the RTDM SPI driver for RPI (spi-bcm2835.c) provided in the Xenomai upstream, even that makes the system lock up. I have enabled IPIPE_DEBUG and tried to see if I get any useful trace but no luck.
GPIO interupts working: I thought to check if the GPIO interrupts also have same issue but fortunately the GPIO interrupts work fine. I suspect (Correct me if I am wrong) it has got to do with the nested irq controllers in bcm2836 and bcm2837 which makes it different from bcm2835. The GPIO irqs are not routed through these interrupt controllers I think and thus the i-pipe patch works fine for bcm2836 as well. It would be great if someone can throw some light onto this problem. Has anyone tried to use real-time SPI or DMA on a RPI 3 ? Or if someone can show some direction in how to fix the irq chips driver it would be very helpful. Thanks, Nitin
