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;
 }