diff options
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/pci.c | 24 |
1 files changed, 11 insertions, 13 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index d068f11d08a7..c9d8e3c837de 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5556,9 +5556,13 @@ enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev) u32 lnkcap2, lnkcap; /* - * PCIe r4.0 sec 7.5.3.18 recommends using the Supported Link - * Speeds Vector in Link Capabilities 2 when supported, falling - * back to Max Link Speed in Link Capabilities otherwise. + * Link Capabilities 2 was added in PCIe r3.0, sec 7.8.18. The + * implementation note there recommends using the Supported Link + * Speeds Vector in Link Capabilities 2 when supported. + * + * Without Link Capabilities 2, i.e., prior to PCIe r3.0, software + * should use the Supported Link Speeds field in Link Capabilities, + * where only 2.5 GT/s and 5.0 GT/s speeds were defined. */ pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2); if (lnkcap2) { /* PCIe r3.0-compliant */ @@ -5574,16 +5578,10 @@ enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev) } pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap); - if (lnkcap) { - if (lnkcap & PCI_EXP_LNKCAP_SLS_16_0GB) - return PCIE_SPEED_16_0GT; - else if (lnkcap & PCI_EXP_LNKCAP_SLS_8_0GB) - return PCIE_SPEED_8_0GT; - else if (lnkcap & PCI_EXP_LNKCAP_SLS_5_0GB) - return PCIE_SPEED_5_0GT; - else if (lnkcap & PCI_EXP_LNKCAP_SLS_2_5GB) - return PCIE_SPEED_2_5GT; - } + if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_5_0GB) + return PCIE_SPEED_5_0GT; + else if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_2_5GB) + return PCIE_SPEED_2_5GT; return PCI_SPEED_UNKNOWN; } |