lan743x: trim all 4 bytes of the FCS; not just 2

Trim all 4 bytes of the received FCS; not just 2 of them. Leaving 2 bytes of the FCS on the frame breaks DSA tailing tag drivers. Fixes: a8db76d ("lan743x: boost performance on cpu archs w/o dma cache snooping") Signed-off-by: George McCollister <[email protected]> Signed-off-by: David S. Miller <[email protected]>
ambv · Mar 5, 2021 · 3e21a10 · 3e21a10
1 parent d8861ba
commit 3e21a10
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c
@@ -2040,7 +2040,7 @@ lan743x_rx_trim_skb(struct sk_buff *skb, int frame_length)
 		dev_kfree_skb_irq(skb);
 		return NULL;
 	}
-	frame_length = max_t(int, 0, frame_length - RX_HEAD_PADDING - 2);
+	frame_length = max_t(int, 0, frame_length - RX_HEAD_PADDING - 4);
 	if (skb->len > frame_length) {
 		skb->tail -= skb->len - frame_length;
 		skb->len = frame_length;