On Thu, May 22, 2014 at 1:17 PM, Borislav Petkov <bp@xxxxxxxxx> wrote: > On Thu, May 22, 2014 at 11:56:03AM -0600, Bjorn Helgaas wrote: >> I chose Fam16h (0x16) because it looks like that's the newest stuff >> that's in the field. I suspect things would probably work if we >> changed this patch to leave ECS disabled on some Fam16h, Fam15h, etc., >> but that would change behavior on existing systems, which obviously >> adds some risk. I didn't think there was much benefit that makes the >> risk worthwhile. >> >> My goal is to stop needing CPU-specific changes in the future, not >> necessarily to remove the CPU-specific code we already have. >> >> Does that make sense? I'm not sure whether I understood your real >> question. > > No, you got it right. I'm just wondering why only the newest stuff. > MMCONFIG is supposed to work just fine on everything from Fam10h > onwards, I'm not sure all Fam10h supported it though. Maybe Suravee can > verify that... Even if MMCONFIG does work fine on everything from Fam10h onwards, we still depend on the BIOS to provide a correct MCFG table. I don't think we can guarantee that changing from ECS to MMCONFIG on a Fam16h box in the field is safe, because we'd then be using a feature we've never used before. Bjorn -- 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
