r8169: remove not needed check in rtl8169_start_xmit

[ Upstream commit bd4bdeb ]

In rtl_tx() the released descriptors are zero'ed by
rtl8169_unmap_tx_skb(). And in the beginning of rtl8169_start_xmit()
we check that enough descriptors are free, therefore there's no way
the DescOwn bit can be set here.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/6965d665-6c50-90c5-70e6-0bb335d4ea47@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: c71e3a5 ("r8169: Fix possible ring buffer corruption on fragmented Tx packets.")
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/ethernet/realtek/r8169_main.c

@@ -4285,17 +4285,12 @@ static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb,
 	bool stop_queue, door_bell;
 	u32 opts[2];
 
-	txd_first = tp->TxDescArray + entry;
-
 	if (unlikely(!rtl_tx_slots_avail(tp))) {
 		if (net_ratelimit())
 			netdev_err(dev, "BUG! Tx Ring full when queue awake!\n");
 		goto err_stop_0;
 	}
 
-	if (unlikely(le32_to_cpu(txd_first->opts1) & DescOwn))
-		goto err_stop_0;
-
 	opts[1] = rtl8169_tx_vlan_tag(skb);
 	opts[0] = 0;
 
@@ -4308,6 +4303,8 @@ static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb,
 				    entry, false)))
 		goto err_dma_0;
 
+	txd_first = tp->TxDescArray + entry;
+
 	if (frags) {
 		if (rtl8169_xmit_frags(tp, skb, opts, entry))
 			goto err_dma_1;