PCI: Decode PCIe 32 GT/s link speed
PCIe r5.0, sec 7.5.3.18, defines a new 32.0 GT/s bit in the Supported Link
Speeds Vector of Link Capabilities 2. Decode this new speed. This does
not affect the speed of the link, which should be negotiated automatically
by the hardware; it only adds decoding when showing the speed to the user.
Previously, reading the speed of a link operating at this speed showed
"Unknown speed" instead of "32.0 GT/s".
Link: https://lore.kernel.org/lkml/92365e3caf0fc559f9ab14bcd053bfc92d4f661c.1559664969.git.gustavo.pimentel@synopsys.com
Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 8abc843..4729a7c 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5621,7 +5621,9 @@ enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev)
*/
pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2);
if (lnkcap2) { /* PCIe r3.0-compliant */
- if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_16_0GB)
+ if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_32_0GB)
+ return PCIE_SPEED_32_0GT;
+ else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_16_0GB)
return PCIE_SPEED_16_0GT;
else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_8_0GB)
return PCIE_SPEED_8_0GT;