On Mon, May 6, 2013 at 11:03 AM, Jon Mason <jon.mason@xxxxxxxxx> wrote:
> Certain NTB devices have a hardware errata where, regardless of
> pre-configured value, reading the BAR size returns 4096. To work around
> this issue, add a PCI quirk to read the appropriate values from an
> alternative register in PCI config space and move the resource endpoints
> to the appropriate location.
Is there a documentation pointer we could add to the changelog?
I applied this to my pci/misc branch. As soon as v3.10-rc1 is out,
I'll rebase to that and incorporate it into -next.
> Signed-off-by: Jon Mason <jon.mason@xxxxxxxxx>
> ---
> drivers/pci/quirks.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 7d68aee..a57a93b 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -2865,6 +2865,30 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x65f9, quirk_intel_mc_errata);
> DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x65fa, quirk_intel_mc_errata);
>
>
> +/* Ivytown NTB BAR sizes are misreported by the hardware due to an errata. To
> + * work around this, query the size it should be configured to by the device and
> + * modify the resource end to correspond to this new size.
> + */
> +static void quirk_intel_ntb(struct pci_dev *dev)
> +{
> + int rc;
> + u8 val;
> +
> + rc = pci_read_config_byte(dev, 0x00D0, &val);
> + if (rc)
> + return;
> +
> + dev->resource[2].end = dev->resource[2].start + ((u64) 1 << val) - 1;
> +
> + rc = pci_read_config_byte(dev, 0x00D1, &val);
> + if (rc)
> + return;
> +
> + dev->resource[4].end = dev->resource[4].start + ((u64) 1 << val) - 1;
> +}
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0e08, quirk_intel_ntb);
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0e0d, quirk_intel_ntb);
> +
> static ktime_t fixup_debug_start(struct pci_dev *dev,
> void (*fn)(struct pci_dev *dev))
> {
> --
> 1.7.9.5
>
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
