I'm not familiar with the chaining of shared interrupts in the RTDM architecture. I think the EOI should somehow be done in the very last invocation of rt_16550_interrupt() by the last peripheral needing service.
I read this from an old interrupt handler: (assuming IBM PC (Intel) architecture) An interrupt handler issues an EOI by writing the value 0x20 to the PIC at address 0x20. If the interrupt was number 8-15, do the same thing again, write 0x20 to address 0x20. So perhaps something like this at the end of rt_16550_interrupt() ? if (ctx->irq_handle.irq <= 7) /* non-specific EOI to 8259 */ rt_16550_reg_out(mode, 0, 0x20, 0x20); if (ctx->irq_handle.irq <= 15) /* extra EOI for upper ISA IRQs */ rt_16550_reg_out(mode, 0, 0x20, 0x20); But again I don't know if that will work with shared interrupts. Surely RTDM implements some "master" handler which is already doing an EOI? Remember lower interrupts like IRQ 5 work fine with the xeno_16550A driver unless another port is sharing the same IRQ. -C Smith _______________________________________________ Xenomai mailing list Xenomai@xenomai.org https://xenomai.org/mailman/listinfo/xenomai
