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 <antoine.tenart@bootlin.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index 8f11fdb..9b8a17e 100644 (file)
--- 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
index 0cf0b09..4c23d18 100644 (file)
--- 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;