ixgbe: warn when device is in a x4 or lower width slot

It's easy to oversee this issue when working with this card
as evrything will work OK but performance is severely limited
(something like 1.5gbit on a x1 link) if the pci-express
slot does not offer more bandwidth.

Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index ead49e54f31b..576fb51eb748 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -2778,6 +2778,14 @@ static int __devinit ixgbe_probe(struct pci_dev *pdev,
                  hw->mac.type, hw->phy.type,
                  (part_num >> 8), (part_num & 0xff));
 
+        if (link_width <= IXGBE_PCI_LINK_WIDTH_4) {
+                dev_warn(&pdev->dev, "PCI-Express bandwidth available for "
+                         "this card is not sufficient for optimal "
+                         "performance.\n");
+                dev_warn(&pdev->dev, "For optimal performance a x8 "
+                         "PCI-Express slot is required.\n");
+        }
+
         /* reset the hardware with the new settings */
         ixgbe_start_hw(hw);