Messages in this thread | | | Subject | Re: [PATCH] arm64: PCI: Validate the node before setting node id for root bus | From | Baolin Wang <> | Date | Sat, 3 Oct 2020 17:35:41 +0800 |
| |
> On Tue, Sep 29, 2020 at 11:41:29PM +0800, Baolin Wang wrote: >> Hi, >> >> 锟斤拷 2020/9/28 23:23, Lorenzo Pieralisi 写锟斤拷: >>> On Mon, Sep 28, 2020 at 10:49:57PM +0800, Baolin Wang wrote: >>>> On Mon, Sep 28, 2020 at 03:00:55PM +0100, Will Deacon wrote: >>>>> [+ Lorenzo] >>>>> >>>>> On Tue, Sep 22, 2020 at 06:33:24PM +0800, Baolin Wang wrote: >>>>>> If the BIOS disabled the NUMA configuration, but did not change the >>>>>> proximity domain description in the SRAT table, so the PCI root bus >>>>>> device may get a incorrect node id by acpi_get_node(). >>>>> >>>>> How "incorrect" are we talking here? What actually goes wrong? At some >>>>> point, we have to trust what the firmware is telling us. >>>> >>>> What I mean is, if we disable the NUMA from BIOS >>> >>> Please define what this means ie are you removing SRAT from ACPI static >>> tables ? >> >> Yes. >> >>> >>>> but we did not change the PXM for the PCI devices, >>> >>> If a _PXM maps to a proximity domain that is not described in the SRAT >>> your firmware is buggy. >> >> Sorry for confusing, that's not what I mean. When the BIOS disable the NUMA >> (remove the SRAT table), but the PCI devices' _PXM description is still >> available, which means we can still get the pxm from acpi_evaluate_integer() >> in this case. > > There should not be a _PXM object if the SRAT is not available, that's > a firmware bug. > >> So we can get below inconsistent log on ARM platform: >> "No NUMA configuration found >> PCI_bus 0000:00 on NUMA node 0 >> ... >> PCI_bus 0000:e3 on NUMA node 1" >> >> On X86, the pci_acpi_root_get_node() will validate the node before setting >> the node id for root bus. So I think we can add this validation for ARM >> platform. Or anything else I missed? > > We are not adding checks because x86 does it, it is certainly to paper > over a firmware bug that you hopefully still have a chance to fix, > let's do that instead of adding code that is not necessary.
Thanks for your input, and I will check this issue with our firmware colleagues again.
| |