On Sat, Sep 17, 2022 at 01:03:09PM +0100, Maciej W. Rozycki wrote:
> Consistently with commit c8b303d0206b ("PCI: Remove PCIe Capability
> version checks") only consider the PCI Express capability's Link Control
> 2, etc. registers present if the Link Control register is.
>
> Before said commit with PCI Express capability versions higher than one
> all link registers used to be considered present, however starting from
> said commit Link Control, etc. original registers are only considered
> present in devices with links, but Link Control 2, etc. registers
> continue being considered always present even though likewise they are
> only present in devices with links.
>
> Fix the inconsistency then.
>
> Signed-off-by: Maciej W. Rozycki <macro@xxxxxxxxxxx>
While we figure out the rest of this, I squashed the first two patches
and applied them to pci/enumeration for v6.2:
commit 503fa23614dc ("PCI: Access Link 2 registers only for devices with Links")
Author: Maciej W. Rozycki <macro@xxxxxxxxxxx>
Date: Sat Sep 17 13:03:09 2022 +0100
PCI: Access Link 2 registers only for devices with Links
PCIe r2.0, sec 7.8 added Link Capabilities/Status/Control 2 registers to
the PCIe Capability with Capability Version 2.
Previously we assumed these registers were implemented for all PCIe
Capabilities of version 2 or greater, but in fact they are only
implemented for devices with Links.
Update pcie_capability_reg_implemented() to check whether the device has
a Link.
> ---
> New change in v5.
> ---
> drivers/pci/access.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> linux-pcie-cap-has-lnkctl2.diff
> Index: linux-macro/drivers/pci/access.c
> ===================================================================
> --- linux-macro.orig/drivers/pci/access.c
> +++ linux-macro/drivers/pci/access.c
> @@ -350,6 +350,11 @@ bool pcie_cap_has_lnkctl(const struct pc
> type == PCI_EXP_TYPE_PCIE_BRIDGE;
> }
>
> +static inline bool pcie_cap_has_lnkctl2(const struct pci_dev *dev)
> +{
> + return pcie_cap_has_lnkctl(dev) && pcie_cap_version(dev) > 1;
> +}
> +
> static inline bool pcie_cap_has_sltctl(const struct pci_dev *dev)
> {
> return pcie_downstream_port(dev) &&
> @@ -390,10 +395,11 @@ static bool pcie_capability_reg_implemen
> return pcie_cap_has_rtctl(dev);
> case PCI_EXP_DEVCAP2:
> case PCI_EXP_DEVCTL2:
> + return pcie_cap_version(dev) > 1;
> case PCI_EXP_LNKCAP2:
> case PCI_EXP_LNKCTL2:
> case PCI_EXP_LNKSTA2:
> - return pcie_cap_version(dev) > 1;
> + return pcie_cap_has_lnkctl2(dev);
> default:
> return false;
> }
