On Fri, Dec 06, 2019 at 03:01:45PM +0800, Xiongfeng Wang wrote:
> HiSilicon PCI Network Processor 5896 devices misreport the class type as
> 'NOT_DEFINED', but it is actually a network device. Also the size of
> BAR3 is reported as 265T, but this BAR is actually unused.
> This patch modify the class type to 'CLASS_NETWORK' and disable the
> unused BAR3.
"NOT_DEFINED" is not the value in the Class Code register. The commit
message should include the actual value.
> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx>
> ---
> drivers/pci/quirks.c | 29 +++++++++++++++++++++++++++++
> include/linux/pci_ids.h | 1 +
> 2 files changed, 30 insertions(+)
>
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 4937a08..b9adebb 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -5431,3 +5431,32 @@ static void quirk_reset_lenovo_thinkpad_p50_nvgpu(struct pci_dev *pdev)
> DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_NVIDIA, 0x13b1,
> PCI_CLASS_DISPLAY_VGA, 8,
> quirk_reset_lenovo_thinkpad_p50_nvgpu);
> +
> +static void quirk_hisi_fixup_np_class(struct pci_dev *pdev)
> +{
> + u32 class = pdev->class;
> +
> + pdev->class = PCI_BASE_CLASS_NETWORK << 8;
> + pci_info(pdev, "PCI class overriden (%#08x -> %#08x)\n",
> + class, pdev->class);
> +}
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_HUAWEI, PCI_DEVICE_ID_HISI_5896,
> + quirk_hisi_fixup_np_class);
> +
> +/*
> + * HiSilicon NP 5896 devices BAR3 size is reported as 256T and causes problem
> + * when assigning the resources. But this BAR is actually unused by the driver,
> + * so let's disable it.
The question is not whether the BAR is used by the driver; the
question is whether the device responds to accesses to the region
described by the BAR when PCI_COMMAND_MEMORY is turned on.
> + */
> +static void quirk_hisi_fixup_np_bar(struct pci_dev *pdev)
> +{
> + struct resource *r = &pdev->resource[3];
> +
> + r->start = 0;
> + r->end = 0;
> + r->flags = 0;
> +
> + pci_info(pdev, "Disabling invalid BAR 3\n");
This quirk clears the Linux *resource* related to the BAR, but it
does nothing with the hardware register itself. There is no way to
disable an individual BAR; all we have is PCI_COMMAND_MEMORY, which
enables/disables all memory BARs as a group.
If this is a device defect, where the config register at 0x1c *looks*
like a BAR, but it actually isn't a BAR and doesn't cause the device
to decode any address space, a quirk like this might be OK. But if
the device does decode address space described by that BAR, we need
more than this.
Can you provide "sudo lspci -vvxxx" output for this device?
> +}
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_HUAWEI, PCI_DEVICE_ID_HISI_5896,
> + quirk_hisi_fixup_np_bar);
> diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
> index 2302d133..f21cd8b 100644
> --- a/include/linux/pci_ids.h
> +++ b/include/linux/pci_ids.h
> @@ -2558,6 +2558,7 @@
> #define PCI_DEVICE_ID_KORENIX_JETCARDF3 0x17ff
>
> #define PCI_VENDOR_ID_HUAWEI 0x19e5
> +#define PCI_DEVICE_ID_HISI_5896 0x5896 /* HiSilicon NP 5896 devices */
>
> #define PCI_VENDOR_ID_NETRONOME 0x19ee
> #define PCI_DEVICE_ID_NETRONOME_NFP4000 0x4000
> --
> 1.7.12.4
>
