Re: [PATCH] x86, quirks: Add workaround for AMD F16h Erratum792

From: Ingo Molnar
Date: Mon Jan 20 2014 - 02:07:57 EST



* Aravind Gopalakrishnan <Aravind.Gopalakrishnan@xxxxxxx> wrote:

> The workaround for this Erratum is included in AGESA. But BIOSes spun
> only after Jan2014 will have the fix (atleast server versions of the
> chip). The erratum affects both client and server platforms and since
> we cannot say with certainity that ALL BIOSes on systems out in the
> field will have the fix, we should probably insulate ourselves in case
> BIOS does not do the right thing or someone is using old BIOSes.
>
> Refer Revision Guide for AMD F16h models 00h-0fh, document 51810
> Rev. 3.04, November2013 for details on the Erratum.
>
> Tested the patch on Fam16h server platform and works fine.
>
> Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@xxxxxxx>
> ---
> arch/x86/kernel/quirks.c | 31 +++++++++++++++++++++++++++++++
> 1 file changed, 31 insertions(+)
>
> diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
> index 04ee1e2..e55ae02 100644
> --- a/arch/x86/kernel/quirks.c
> +++ b/arch/x86/kernel/quirks.c
> @@ -571,3 +571,34 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F5,
> quirk_amd_nb_node);
>
> #endif
> +
> +#if defined(CONFIG_PCI)
> +/*
> + * Apply AMD Fam16h Erratum792
> + * see Revision Guide for AMD F16h models 00h-0fh,
> + * document 51810 rev. 3.04, Nov 2013
> + */
> +static void quirk_amd_dram_scrub(struct pci_dev *dev)

The reference to the erratum is useful for people who want to see more
details, but at least a short description of the problem being fixed
and systems affected by the quirk is needed. 'DRAM scrub' is not very
informative.

Thanks,

Ingo
--
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/