On Fri, 29 Aug 2008, Yinghai Lu wrote:

quoted text
>

> 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

quoted text
> 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

quoted text
> 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

quoted text
>        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,

quoted text
> 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

quoted text
> insert_resource_expand_to_fit...

Yes. And I do think this is a workable model.
			Linus

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