On Tue, 2019-03-12 at 10:08 -0700, Greg Kroah-Hartman wrote:
4.20-stable review patch. If anyone has any objections, please let me know.
[ Upstream commit c5acdbee22a1b200dde07effd26fd1f649e9ab8a ]
The number of TSO enabled channels in HW can be different than the number of total channels. There is no way to determined, at runtime, the number of TSO capable channels and its safe to assume that if TSO is enabled then at least channel 0 will be TSO capable.
Lets always send TSO packets from Queue 0.
Signed-off-by: Jose Abreu joabreu@synopsys.com Cc: Joao Pinto jpinto@synopsys.com Cc: David S. Miller davem@davemloft.net Cc: Giuseppe Cavallaro peppe.cavallaro@st.com Cc: Alexandre Torgue alexandre.torgue@st.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 5d83d6a7694b..f76f6ae3fa87 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -3033,8 +3033,17 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev) /* 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))
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);
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.
Ben.
return stmmac_tso_xmit(skb, dev);
}if (unlikely(stmmac_tx_avail(priv, queue) < nfrags + 1)) {