net: mscc: allow extracting the FCS into the skb

This patch adds support for the NETIF_F_RXFCS feature in the Mscc Ethernet driver. This feature is disabled by default and allow a user to request the driver not to drop the FCS and to extract it into the skb for debugging purposes. Signed-off-by: Antoine Tenart <[email protected]> Reviewed-by: Alexandre Belloni <[email protected]> Signed-off-by: David S. Miller <[email protected]>
CarlFK · Oct 11, 2018 · 60f8e67 · 60f8e67
1 parent b7ec45a
commit 60f8e67
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Showing 2 changed files with 7 additions and 2 deletions.
diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
@@ -1620,7 +1620,7 @@ int ocelot_probe_port(struct ocelot *ocelot, u8 port,
 	dev->ethtool_ops = &ocelot_ethtool_ops;
 	dev->switchdev_ops = &ocelot_port_switchdev_ops;
 
-	dev->hw_features |= NETIF_F_HW_VLAN_CTAG_FILTER;
+	dev->hw_features |= NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_RXFCS;
 	dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
 
 	memcpy(dev->dev_addr, ocelot->base_mac, ETH_ALEN);

diff --git a/drivers/net/ethernet/mscc/ocelot_board.c b/drivers/net/ethernet/mscc/ocelot_board.c
@@ -128,11 +128,16 @@ static irqreturn_t ocelot_xtr_irq_handler(int irq, void *arg)
 			len += sz;
 		} while (len < buf_len);
 
-		/* Read the FCS and discard it */
+		/* Read the FCS */
 		sz = ocelot_rx_frame_word(ocelot, grp, false, &val);
 		/* Update the statistics if part of the FCS was read before */
 		len -= ETH_FCS_LEN - sz;
 
+		if (unlikely(dev->features & NETIF_F_RXFCS)) {
+			buf = (u32 *)skb_put(skb, ETH_FCS_LEN);
+			*buf = val;
+		}
+
 		if (sz < 0) {
 			err = sz;
 			break;