Re: [PATCH V5 0/4] x86/pci Fix numa_node info for AMD hostbridge and misc clean up

From: Suravee Suthikulanit
Date: Thu May 22 2014 - 20:49:25 EST


[Resending due to mail client crashing]

On 5/21/2014 6:17 PM, Bjorn Helgaas wrote:
[resending because I forgot to copy the lists, sorry guys]

Hi Suravee,

Sorry it took me so long to get to these patches. Here's my proposal. I
reordered them and added some comments in the code and changelogs, but I
think your patches look fine as-is.

So I just need comments on these two significant changes:

1) I added a patch to stop enabling ECS after Fam16h, because that's
another case of CPU-dependent code that we should not need to keep
carrying. I don't think there are any post-Fam16h CPUs yet, but I
certainly don't want to do anything that will keep them from working when
they do arrive. It would be useful if somebody could test this on
current platforms by tweaking the patch so we don't enable ECS on Fam15h.

I'm okay with this. In my V4 patch, I also tested disabling ECS on family15h already and that seems to work fine. But I would not mind deprecate this for post fam16h processors.


2) I dropped the quirk_amd_nb_node() removal. I could be convinced
otherwise, but I don't really object to the quirk because it is already
explicitly limited to specific devices, and removing it will change
things in sysfs. I think the changes would be harmless as far as the
kernel is concerned, since there are no drivers for these devices. But
Andreas added the quirk because of complaints, so apparently somebody is
looking at what's in sysfs, and I don't want to get the same complaints
again by removing it. However, I will certainly ask questions if I see
the quirk being extended to more devices.

I'm okay with keeping this.

The AMD BKDG does say the BIOS should provide an MCFG table (sec 2.8 of
42301), so I think it provides guidance matching the intent of my "stop
enabling ECS" patch. But the BKDG doesn't mention _PXM at all. Is there
any chance you could squeeze in a mention of that, so BIOS writers know
that they *should* provide it? I want to avoid more fire-drills in the
future.

Bjorn

The ship for family15h stuff have sailed and we probably would not be able to get them to change. We are going to have to keep an eye on the future platforms to make sure that the _PXM info is documented for future platforms.

I have tested this patch set and they seems to be ok now.

Suravee


---

Bjorn Helgaas (1):
x86/PCI: Stop enabling ECS for AMD CPUs after Fam16h

Myron Stowe (1):
x86/PCI: Warn if we have to "guess" host bridge node information

Suravee Suthikulpanit (2):
x86/PCI: Work around AMD Fam15h BIOSes that fail to provide _PXM
x86/PCI: Clean up and mark early_root_info_init() as deprecated


arch/x86/pci/acpi.c | 6 +++
arch/x86/pci/amd_bus.c | 87 +++++++++++++++++++++++++++++++-----------------
2 files changed, 62 insertions(+), 31 deletions(-)


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/