On Fri, 29 Aug 2008, Yinghai Lu wrote: > > the root cause is: > before 2.6.26, call init_apic_mapping and will insert_resource for > lapic address. > and then call e820_resource_resouce (with request_resource) to > register e820 entries. So the problem there was that traditionally, e820_reserve_resource() expected to be the first one to populate any resources. That's changed, and that's why it now needs to use "insert_resource()" rather than "request_resource()". > so the lapic entry in the resource tree will prevent some entry in > e820 to be registered. > later request_resource for BAR res (==hpet) will succeed. > > from 2.6.26. we move lapic address registering to late_initcall, so > the entry is reserved in e820 getting into resource tree at first. > and later pci_resource_survey::request_resource for BAR res (==hpet, > 0xfed00000) will fail. so pci_assign_unsigned... will get new > res for the BAR, so it messed up hpet setting. So this didn't work _originally_ either? > solutions will be > 1. use quirk to protect hpet in BAR, Ingo said it is not generic. Yeah, I don't like it. The quirk I was talking about was the one about apparetly bogus MMIO address: >> pci 0000:00:00.0: BAR has MMCONFIG at e0000000-ffffffff > PCI: Using MMCONFIG at e0000000 - efffffff > > Where did it get that bogus "ffffffff" end address? which you said came from another BAR. That isn't the HPET. > 2. or the one you are reverted... check_bar_with_valid. (hpet, ioapic, > mmconfig) --> happenly reveal another problem with Rafael's > system/chipset. Yeah, no, that's horrid. I'm happy it's reverted. > 3. or sticky resource... , but could have particallly overlapping And no, this doesn't work. > 4. or don't register reserved entries in e820.. Eric, Nacked. Yeah, no, we do want reserved entries from e820 to show up to at least stop late _dynamic_ allocations from taking over. > 5. or you sugges, regiser some reserved entries later...., and have > insert_resource_expand_to_fit... Yes. And I do think this is a workable model. Linus -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
