Messages in this thread | | | Date | Thu, 28 Aug 2008 13:19:30 -0700 | From | "Yinghai Lu" <> | Subject | Re: [PATCH] x86: split e820 reserved entries record to late |
| |
On Thu, Aug 28, 2008 at 1:05 PM, Linus Torvalds <torvalds@linux-foundation.org> wrote: > > > On Thu, 28 Aug 2008, Yinghai Lu wrote: >> >> so could let BAR res register at first, or even pnp? > > Well, I'm not sure whether PnP or e820 should be first, as long as any > "real hardware" probing takes precedence over either. I _suspect_ that > e820 is more trustworthy, which implies that PnP should probably be added > last. It would be good to have some idea what Windows does, since usually > all the firmware bugs are essentially hidden by whatever that other OS > happens to do. > > The basic rule really should be: "What do we trust most?" and probe things > in that order. > > So e820 is fairly trustworthy, but we know that it will have various > random things marked as reserved because they are special in some way (but > we don't know _how_ they are special - they may well be real BAR's that > just have a fixed meaning to ACPI or whatever). > > But we obviously trust _part_ of it (the RAM stuff) more than we trust > other parts. So it does make sense to consider that separately. > > PnP I personally wouldn't trust at all, except as a way to keep dynamic > resources away from those things, which is why I'd put it last. But that's > just my personal gut feeling. > > Hardware we generally trust more than any firmware, but even hardware can > have bugs. And some classes of hardware tends to be less buggy than others > (ie I'd trust some on-die APIC base pointer before I would trust a Cardbus > controller BAR, for example).
ok, will move e820_reserve_resource_late to pcibios_resource_survey(), so it is called vi pci_subsys_init before pnp_system_init
YH
| |