Re: [PATCH v2 3/3] PCI: Support PCIe Capability Slot registers onlyfor ports with slots

[Myron Stowe]

On Tue, Nov 19, 2013 at 2:35 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote:
> Commit 6d3a1741f1e648cfbd5a0cc94477a0d5004c6f5e upstream.  This is part
> of the fix for https://bugzilla.kernel.org/show_bug.cgi?id=65211
>
> Previously we allowed callers to access Slot Capabilities, Status, and
> Control for Root Ports even if the Root Port did not implement a slot.
> This seems dubious because the spec only requires these registers if a
> slot is implemented.
>
> It's true that even Root Ports without slots must have *space* for these
> slot registers, because the Root Capabilities, Status, and Control
> registers are after the slot registers in the capability.  However,
> for a v1 PCIe Capability, the *semantics* of the slot registers are
> undefined unless a slot is implemented.
>
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Reviewed-By: Jiang Liu <jiang.liu@xxxxxxxxxx>
> CC: stable@xxxxxxxxxxxxxxx      # v3.7+
> ---
>  drivers/pci/access.c |    6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/access.c b/drivers/pci/access.c
> index 9a46fa9135d9..061da8c3ab4b 100644
> --- a/drivers/pci/access.c
> +++ b/drivers/pci/access.c
> @@ -497,9 +497,9 @@ static inline bool pcie_cap_has_sltctl(const struct pci_dev *dev)
>  {
>         int type = pci_pcie_type(dev);
>
> -       return type == PCI_EXP_TYPE_ROOT_PORT ||
> -              (type == PCI_EXP_TYPE_DOWNSTREAM &&
> -               pcie_caps_reg(dev) & PCI_EXP_FLAGS_SLOT);
> +       return (type == PCI_EXP_TYPE_ROOT_PORT ||
> +               type == PCI_EXP_TYPE_DOWNSTREAM) &&
> +              pcie_caps_reg(dev) & PCI_EXP_FLAGS_SLOT;
>  }
>
>  static inline bool pcie_cap_has_rtctl(const struct pci_dev *dev)
>

Acked-by: Myron Stowe <myron.stowe@xxxxxxxxxx>

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