On Fri, Apr 15, 2005 at 02:36:51PM -0700, Shawn Jin wrote: > > The home-made interrupt controller PIC supports interrupt priorities > and critical/non-critical interrupts. I found that the current kernel > doesn't support interrupt priorities.
Yes, we don't have IRQ priorities on 4xx. Theoretically, they can be emulated in get_irq, but I really don't think it's worth it. > Is this observation true? Is > there any existing patch to support that? I'm not aware of such patch existence. > I noticed that the implementation of ppc4xx_pic.c disables all > critical interrupts during initialization. To support critical > interrupts, is it so simple that we change the handler of critical > exception from CriticalInput to do_IRQ in head_44x.S? No, it's not that simple. Linux doesn't support a notion of critical IRQs versus normal ones. Until there is an infrastructure for this, it doesn't make any sense to implement 4xx support. -- Eugene
