From: Jose Abreu Jose.Abreu@synopsys.com
[ Upstream commit 4993e5b37e8bcb55ac90f76eb6d2432647273747 ]
Ben Hutchings says: "This is the wrong place to change the queue mapping. stmmac_xmit() is called with a specific TX queue locked, and accessing a different TX queue results in a data race for all of that queue's state.
I think this commit should be reverted upstream and in all stable branches. Instead, the driver should implement the ndo_select_queue operation and override the queue mapping there."
Fixes: c5acdbee22a1 ("net: stmmac: Send TSO packets always from Queue 0") Suggested-by: Ben Hutchings ben@decadent.org.uk Signed-off-by: Jose Abreu joabreu@synopsys.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 29 ++++++++++++++-------- 1 file changed, 19 insertions(+), 10 deletions(-)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -3036,17 +3036,8 @@ static netdev_tx_t stmmac_xmit(struct sk
/* Manage oversized TCP frames for GMAC4 device */ if (skb_is_gso(skb) && priv->tso) { - if (skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)) { - /* - * There is no way to determine the number of TSO - * capable Queues. Let's use always the Queue 0 - * because if TSO is supported then at least this - * one will be capable. - */ - skb_set_queue_mapping(skb, 0); - + if (skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)) return stmmac_tso_xmit(skb, dev); - } }
if (unlikely(stmmac_tx_avail(priv, queue) < nfrags + 1)) { @@ -3855,6 +3846,23 @@ static int stmmac_setup_tc(struct net_de } }
+static u16 stmmac_select_queue(struct net_device *dev, struct sk_buff *skb, + struct net_device *sb_dev, + select_queue_fallback_t fallback) +{ + if (skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)) { + /* + * There is no way to determine the number of TSO + * capable Queues. Let's use always the Queue 0 + * because if TSO is supported then at least this + * one will be capable. + */ + return 0; + } + + return fallback(dev, skb, NULL) % dev->real_num_tx_queues; +} + static int stmmac_set_mac_address(struct net_device *ndev, void *addr) { struct stmmac_priv *priv = netdev_priv(ndev); @@ -4097,6 +4105,7 @@ static const struct net_device_ops stmma .ndo_tx_timeout = stmmac_tx_timeout, .ndo_do_ioctl = stmmac_ioctl, .ndo_setup_tc = stmmac_setup_tc, + .ndo_select_queue = stmmac_select_queue, #ifdef CONFIG_NET_POLL_CONTROLLER .ndo_poll_controller = stmmac_poll_controller, #endif