net/igb/e1000/e1000e: more robust ethtool duplex/speed configuration

This makes sure that one cannot request a 99Mbps full-duplex and get a
100Mbps half-duplex configuration in return due to the way the
speed/duplex parameters are handled internally.

Tested: e1000 works
Signed-off-by: David Decotigny <decot@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 17 insertions, 10 deletions

diff --git a/drivers/net/igb/igb.h b/drivers/net/igb/igb.h
index 1c687e298d5e..f4fa4b1751cf 100644
--- a/drivers/net/igb/igb.h
+++ b/drivers/net/igb/igb.h
@@ -360,7 +360,7 @@ extern int igb_up(struct igb_adapter *);
 extern void igb_down(struct igb_adapter *);
 extern void igb_reinit_locked(struct igb_adapter *);
 extern void igb_reset(struct igb_adapter *);
-extern int igb_set_spd_dplx(struct igb_adapter *, u16);
+extern int igb_set_spd_dplx(struct igb_adapter *, u32, u8);
 extern int igb_setup_tx_resources(struct igb_ring *);
 extern int igb_setup_rx_resources(struct igb_ring *);
 extern void igb_free_tx_resources(struct igb_ring *);
diff --git a/drivers/net/igb/igb_ethtool.c b/drivers/net/igb/igb_ethtool.c
index 023aa9b10654..6e29634b1fb5 100644
--- a/drivers/net/igb/igb_ethtool.c
+++ b/drivers/net/igb/igb_ethtool.c
@@ -224,7 +224,7 @@ static int igb_set_settings(struct net_device *netdev, struct ethtool_cmd *ecmd)
                         hw->fc.requested_mode = e1000_fc_default;
         } else {
                 u32 speed = ethtool_cmd_speed(ecmd);
-                if (igb_set_spd_dplx(adapter, speed + ecmd->duplex)) {
+                if (igb_set_spd_dplx(adapter, speed, ecmd->duplex)) {
                         clear_bit(__IGB_RESETTING, &adapter->state);
                         return -EINVAL;
                 }
diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index cdfd57271051..ce7838e55827 100644
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -6349,21 +6349,25 @@ static void igb_restore_vlan(struct igb_adapter *adapter)
         }
 }
 
-int igb_set_spd_dplx(struct igb_adapter *adapter, u16 spddplx)
+int igb_set_spd_dplx(struct igb_adapter *adapter, u32 spd, u8 dplx)
 {
         struct pci_dev *pdev = adapter->pdev;
         struct e1000_mac_info *mac = &adapter->hw.mac;
 
         mac->autoneg = 0;
 
+        /* Make sure dplx is at most 1 bit and lsb of speed is not set
+         * for the switch() below to work */
+        if ((spd & 1) || (dplx & ~1))
+                goto err_inval;
+
         /* Fiber NIC's only allow 1000 Gbps Full duplex */
         if ((adapter->hw.phy.media_type == e1000_media_type_internal_serdes) &&
-                spddplx != (SPEED_1000 + DUPLEX_FULL)) {
-                dev_err(&pdev->dev, "Unsupported Speed/Duplex configuration\n");
-                return -EINVAL;
-        }
+            spd != SPEED_1000 &&
+            dplx != DUPLEX_FULL)
+                goto err_inval;
 
-        switch (spddplx) {
+        switch (spd + dplx) {
         case SPEED_10 + DUPLEX_HALF:
                 mac->forced_speed_duplex = ADVERTISE_10_HALF;
                 break;
@@ -6382,10 +6386,13 @@ int igb_set_spd_dplx(struct igb_adapter *adapter, u16 spddplx)
                 break;
         case SPEED_1000 + DUPLEX_HALF: /* not supported */
         default:
-                dev_err(&pdev->dev, "Unsupported Speed/Duplex configuration\n");
-                return -EINVAL;
+                goto err_inval;
         }
         return 0;
+
+err_inval:
+        dev_err(&pdev->dev, "Unsupported Speed/Duplex configuration\n");
+        return -EINVAL;
 }
 
 static int __igb_shutdown(struct pci_dev *pdev, bool *enable_wake)