On Fri, Aug 26, 2011 at 09:21:05PM +1000, Finn Thain wrote:
On Fri, 26 Aug 2011, Geert Uytterhoeven wrote:According to via_register_interrupts(), it requests both: if (via_alt_mapping) { if (request_irq(IRQ_AUTO_1, via1_irq, 0, "software", (void *)via1)) pr_err("Couldn't register %s interrupt\n", "software"); if (request_irq(IRQ_AUTO_6, via1_irq, 0, "via1", (void *)via1)) pr_err("Couldn't register %s interrupt\n", "via1"); } else { if (request_irq(IRQ_AUTO_1, via1_irq, 0, "via1", (void *)via1)) pr_err("Couldn't register %s interrupt\n", "via1"); } Hence IRQ_AUTO_1 must be shared and we cannot use an optimized chain handler for via1_irq()I'm pretty sure that the "software" request_irq can be removed. It has come up before -- http://marc.info/?l=linux-mac68k&m=110973724208746&w=2 Maybe Brad can shed some light on this (?)
Sorry, not really. We don't have any good documentation on how the alternate mapping really works on those systems. Anything that has it internally is using custom chips instead of a real VIA6522, so it's hard to say exactly how it behaves. The real key of the alternate mapping is to move the timer interrupt higher than all the other hardware. This and the ADB are about all we really need from VIA1. It's possible one of the other interrupts we don't use is still on IRQ1. It's hard to say without trying. I think I have a couple systems that have this hardware, but they are ones I haven't used much. If I can find some time I'll get the Q950 I acquired recently up and running since it should have the alternate mapping capability. One potential option is to just take it out and see if anything breaks with the change. We could add it back later if we find a use for it. Brad Boyer flar@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-m68k" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
