Messages in this thread | | | Date | Thu, 6 Mar 2014 00:30:37 -0600 | From | Suravee Suthikulpanit <> | Subject | Re: [PATCH 0/3] amd/pci: Add AMD hostbridge supports for newer AMD systems |
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On 3/5/2014 8:13 PM, Suravee Suthikulanit wrote: > On 3/5/2014 3:24 PM, Bjorn Helgaas wrote: >> [+cc linux-acpi] >> >> On Wed, Mar 5, 2014 at 2:06 PM, <suravee.suthikulpanit@amd.com> wrote: >>> From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> >>> >>> The current code only supports upto AMD hostbridge for family11h. >>> This causes PCI numa_node information to be reported incorrectly >>> for newer family with multi sockets. >> >> Where is the incorrect reporting? In ACPI tables? Is this patch a >> way to cover up firmware defects in the ACPI description? Or is this >> for machines without ACPI (it seems unlikely that machines with new >> AMD processors would not have ACPI)? > > This is incorrectly reported in the sysfs for each PCI device (e.g. > /devices/pci0000:50/0000:50:00.2/numa_node). Without the patch, they > return -1. > > In file arch/x86/pci/acpi.c, in function pci_acpi_scan_root(), it is > queries the node information as following: > > #ifdef CONFIG_ACPI_NUMA > pxm = acpi_get_pxm(device->handle); > if (pxm >= 0) > node = pxm_to_node(pxm); > if (node != -1) > set_mp_bus_to_node(busnum, node); > else > #endif > node = get_mp_bus_to_node(busnum); > > In this case, I see that the acpi_get_pxm() returns -1. Therefore, it > falls back to using the node information in mp_bus_to_node[]. So, > without this patch, it would also returning -1. > > Also, the spec mentioned that the _PXM is optional, so I am not sure if > this is a firmware bug. > > Suravee
I am not quite familiar with the ACPI for this part. However, after taking a look at the code (in driver/acpi/pci_root.c: acpi_pci_root_add()), I believe it's trying to locate _PXM method in the DSDT table, in which I don't see any _PXM methods.
I'm still trying to debug this issue, any suggestions would be appreciated.
Thank you,
Suravee
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