Re: stmmac ethernet in kernel 4.9-rc6: coalescing related pauses.
From: Pavel Machek <hidden>
Date: 2016-11-24 10:29:06
Also in:
lkml
Subsystem:
networking drivers, stmmac ethernet driver, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Maxime Chevallier, Linus Torvalds
Hi!
What is going on with stmmac_tso_xmit() vs. stmmac_xmit()? One seems
to be copy of another, with subtle differences -- like calling
netif_queue_stopped() under spin_lock(&priv->tx_lock), or not.
What is going on with all these likely()s? Likely new hardware owners
will not be happy... or anyone running a lot of jumbo frames. (Perhaps
CPU's branch prediction can do better job here, without explicit hints?)
if (unlikely(is_jumbo) && likely(priv->synopsys_id <
DWMAC_CORE_4_00)) {
Are you sure this is okay?
if (unlikely(netif_queue_stopped(priv->dev) &&
stmmac_tx_avail(priv) > STMMAC_TX_THRESH)) {
netif_tx_lock(priv->dev);
if (netif_queue_stopped(priv->dev) &&
stmmac_tx_avail(priv) > STMMAC_TX_THRESH) {
---
Fix english in comments.
Signed-off-by: Pavel Machek <redacted>
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 1f9ec02..e5a5a05 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c@@ -1747,11 +1747,11 @@ static int stmmac_hw_setup(struct net_device *dev, bool init_ptp) if (priv->hw->pcs && priv->hw->mac->pcs_ctrl_ane) priv->hw->mac->pcs_ctrl_ane(priv->hw, 1, priv->hw->ps, 0); - /* set TX ring length */ + /* Set TX ring length */ if (priv->hw->dma->set_tx_ring_len) priv->hw->dma->set_tx_ring_len(priv->ioaddr, (DMA_TX_SIZE - 1)); - /* set RX ring length */ + /* Set RX ring length */ if (priv->hw->dma->set_rx_ring_len) priv->hw->dma->set_rx_ring_len(priv->ioaddr, (DMA_RX_SIZE - 1));
@@ -2212,7 +2212,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev) priv->tx_skbuff[first_entry] = skb; enh_desc = priv->plat->enh_desc; - /* To program the descriptors according to the size of the frame */ + /* Program the descriptors according to the size of the frame */ if (enh_desc) is_jumbo = priv->hw->mode->is_jumbo_frm(skb->len, enh_desc);
@@ -2665,7 +2665,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit) * @budget : maximum number of packets that the current CPU can receive from * all interfaces. * Description : - * To look at the incoming frames and clear the tx resources. + * Look at the incoming frames and clear the tx resources. */ static int stmmac_poll(struct napi_struct *napi, int budget) {
@@ -2828,7 +2828,7 @@ static irqreturn_t stmmac_interrupt(int irq, void *dev_id) return IRQ_NONE; } - /* To handle GMAC own interrupts */ + /* Handle GMAC own interrupts */ if ((priv->plat->has_gmac) || (priv->plat->has_gmac4)) { int status = priv->hw->mac->host_irq_status(priv->hw, &priv->xstats);
@@ -2853,7 +2853,7 @@ static irqreturn_t stmmac_interrupt(int irq, void *dev_id) } } - /* To handle DMA interrupts */ + /* Handle DMA interrupts */ stmmac_dma_interrupt(priv); return IRQ_HANDLED;
@@ -3145,7 +3145,7 @@ static int stmmac_hw_init(struct stmmac_priv *priv) priv->hw = mac; - /* To use the chained or ring mode */ + /* Use the chained or ring mode */ if (priv->synopsys_id >= DWMAC_CORE_4_00) { priv->hw->mode = &dwmac4_ring_mode_ops; } else {
@@ -3191,7 +3191,7 @@ static int stmmac_hw_init(struct stmmac_priv *priv) } else pr_info(" No HW DMA feature register supported"); - /* To use alternate (extended), normal or GMAC4 descriptor structures */ + /* Use alternate (extended), normal or GMAC4 descriptor structures */ if (priv->synopsys_id >= DWMAC_CORE_4_00) priv->hw->desc = &dwmac4_desc_ops; else
--
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