On Sat, 18 Apr 2009, Ingo Molnar wrote: > > Am i missing something? We also try to avoid random motherboard resources etc that aren't reserved or documented by the BIOS. It's better to go into big holes. It's also better to try to keep as close to the old (tested) behavior. Now, admittedly those undocumented resources are _much_ more common in IO space, but still. They're _very_ common. Om my modern Nehalem thing with an Intel BIOS (supposedly "good" and not from some random manufacturer), I have, for example: [ 26.533771] pci 0000:00:1f.0: ICH7 LPC Generic IO decode 2 PIO at 0810 (mask 007f) byt that one isn't covered by any PnP range or anythign else. [ Now, it's possible that it's bogus: "0x810" has a bit set in the same bits that cover the mask, and I don't know if the mask is a "ignore these bits" (and the range would thus match all of 0x0800-0x087f) or if the mast is a "port & ~mask == base" in which case nothing would ever match. But I _think_ the BIOS literally set up something to answer int he 0x08?? range, and didn't document it anywhere. The same can be true of MMIO too, and so we should try to avoid using random memory areas if we can ] Linus -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
