Hi,
I was trying to upgrade my application running on Viper
(2.6.16.28 kernel with xenomai 2.3.1) to
kernel 2.6.30.10 with xenomai 2.4.10 and ran into couple of
problems.
1. My application uses real-time hook to CPLD interrupt, which
is chained interrupt.
In Xenomai 2.4.10 for some reason general
purpose interrupt handler for chained interrupt is assigned to I-pipe
acknowledgment handler during board initialization:
in kernel/irq/chip.c:
_set_irq_hanler(...
#ifdef CONFIG_IPIPE
else if (is_chained) {
desc->ipipe_ack = handle;
desc->ipipe_end = &__ipipe_noend_irq;
handle = &__ipipe_noack_irq;
#endif
As a result, when CPLD interrupt happened, general purpose
interrupt from Linux domain is executed as part of ipipe interrupt acknowledgment.
After that my real-time interrupt handler gets executed. This is not normal, as
my handler supposed to replace general purpose handler, which should not be
executed at all, unless I want it to be executed. I fixed this
problem by reassigning ipipe acknowledgment to __ipipe_ack_edge_irq, and not
changing handler at all, and it worked in my case. But this probably can break
some other code.
2. USB on Viepr is not working with I-pipe.
I found the cause of this problem. Again for some reason,
I-pipe patch changes type of the USB and all other multiplexed interrupts from
edge to level interrupt, which they are in original Linux kernel. Of course,
this breaks everything. I fixed USB by changing back interrupts type from level
to edge in arch/arm/plat-pxa/gpio.c:
void __intit pxa_init_gpio(
instead
of
#ifndef CONFIG_IPIPE
set_irq_handler(irq,handle_edge_irq);
#else
set_irq_handler(irq,handle_level_irq);
#endif
I'm using just
set_irq_handler(irq,handle_edge_irq);
, as it was in original Linux code and everything works
fine.
Shouldn't changes to interrupt code in Xenomai depend on particular
board and not be part of the common code?
I would appreciate any response regarding these issues.
Regards,
Ivan