This is a note to let you know that I've just added the patch titled net: stmmac: fix handling of zero coalescing tx-usecs to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-stmmac-fix-handling-of-zero-coalescing-tx-usecs.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit ceac954973be9b2c0db11fae9790c5a1dacaf1ff Author: Vincent Whitchurch <vincent.whitchurch@xxxxxxxx> Date: Thu Sep 7 12:46:31 2023 +0200 net: stmmac: fix handling of zero coalescing tx-usecs [ Upstream commit fa60b8163816f194786f3ee334c9a458da7699c6 ] Setting ethtool -C eth0 tx-usecs 0 is supposed to disable the use of the coalescing timer but currently it gets programmed with zero delay instead. Disable the use of the coalescing timer if tx-usecs is zero by preventing it from being restarted. Note that to keep things simple we don't start/stop the timer when the coalescing settings are changed, but just let that happen on the next transmit or timer expiry. Fixes: 8fce33317023 ("net: stmmac: Rework coalesce timer and fix multi-queue races") Signed-off-by: Vincent Whitchurch <vincent.whitchurch@xxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index a07bcb2f5d2e2..1559a4dafd413 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -2692,9 +2692,7 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue) /* We still have pending packets, let's call for a new scheduling */ if (tx_q->dirty_tx != tx_q->cur_tx) - hrtimer_start(&tx_q->txtimer, - STMMAC_COAL_TIMER(priv->tx_coal_timer[queue]), - HRTIMER_MODE_REL); + stmmac_tx_timer_arm(priv, queue); __netif_tx_unlock_bh(netdev_get_tx_queue(priv->dev, queue)); @@ -2975,9 +2973,13 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv) static void stmmac_tx_timer_arm(struct stmmac_priv *priv, u32 queue) { struct stmmac_tx_queue *tx_q = &priv->dma_conf.tx_queue[queue]; + u32 tx_coal_timer = priv->tx_coal_timer[queue]; + + if (!tx_coal_timer) + return; hrtimer_start(&tx_q->txtimer, - STMMAC_COAL_TIMER(priv->tx_coal_timer[queue]), + STMMAC_COAL_TIMER(tx_coal_timer), HRTIMER_MODE_REL); }