[PATCH net 11/11] net: stmmac: Fix the TX IOC in xmit path

[Jose Abreu]

IOC bit must be only set in the last descriptor. Move the logic up a
little bit to make sure it's set in the correct descriptor.

Signed-off-by: Jose Abreu <Jose.Abreu@xxxxxxxxxxxx>

---
Cc: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
Cc: Alexandre Torgue <alexandre.torgue@xxxxxx>
Cc: Jose Abreu <joabreu@xxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: linux-stm32@xxxxxxxxxxxxxxxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 64 ++++++++++++-----------
 1 file changed, 34 insertions(+), 30 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index b0a16d7c6e3d..f826365c979d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3024,6 +3024,19 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
 	/* Only the last descriptor gets to point to the skb. */
 	tx_q->tx_skbuff[tx_q->cur_tx] = skb;
 
+	/* Manage tx mitigation */
+	tx_q->tx_count_frames += nfrags + 1;
+	if (likely(priv->tx_coal_frames > tx_q->tx_count_frames) &&
+	    !((skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) &&
+	      priv->hwts_tx_en)) {
+		stmmac_tx_timer_arm(priv, queue);
+	} else {
+		desc = &tx_q->dma_tx[tx_q->cur_tx];
+		tx_q->tx_count_frames = 0;
+		stmmac_set_tx_ic(priv, desc);
+		priv->xstats.tx_set_ic_bit++;
+	}
+
 	/* We've used all descriptors we need for this skb, however,
 	 * advance cur_tx so that it references a fresh descriptor.
 	 * ndo_start_xmit will fill this descriptor the next time it's
@@ -3041,19 +3054,6 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
 	priv->xstats.tx_tso_frames++;
 	priv->xstats.tx_tso_nfrags += nfrags;
 
-	/* Manage tx mitigation */
-	tx_q->tx_count_frames += nfrags + 1;
-	if (likely(priv->tx_coal_frames > tx_q->tx_count_frames) &&
-	    !(priv->synopsys_id >= DWMAC_CORE_4_00 &&
-	    (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) &&
-	    priv->hwts_tx_en)) {
-		stmmac_tx_timer_arm(priv, queue);
-	} else {
-		tx_q->tx_count_frames = 0;
-		stmmac_set_tx_ic(priv, desc);
-		priv->xstats.tx_set_ic_bit++;
-	}
-
 	if (priv->sarc_type)
 		stmmac_set_desc_sarc(priv, first, priv->sarc_type);
 
@@ -3225,6 +3225,27 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	/* Only the last descriptor gets to point to the skb. */
 	tx_q->tx_skbuff[entry] = skb;
 
+	/* According to the coalesce parameter the IC bit for the latest
+	 * segment is reset and the timer re-started to clean the tx status.
+	 * This approach takes care about the fragments: desc is the first
+	 * element in case of no SG.
+	 */
+	tx_q->tx_count_frames += nfrags + 1;
+	if (likely(priv->tx_coal_frames > tx_q->tx_count_frames) &&
+	    !((skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) &&
+	      priv->hwts_tx_en)) {
+		stmmac_tx_timer_arm(priv, queue);
+	} else {
+		if (likely(priv->extend_desc))
+			desc = &tx_q->dma_etx[entry].basic;
+		else
+			desc = &tx_q->dma_tx[entry];
+
+		tx_q->tx_count_frames = 0;
+		stmmac_set_tx_ic(priv, desc);
+		priv->xstats.tx_set_ic_bit++;
+	}
+
 	/* We've used all descriptors we need for this skb, however,
 	 * advance cur_tx so that it references a fresh descriptor.
 	 * ndo_start_xmit will fill this descriptor the next time it's
@@ -3260,23 +3281,6 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	dev->stats.tx_bytes += skb->len;
 
-	/* According to the coalesce parameter the IC bit for the latest
-	 * segment is reset and the timer re-started to clean the tx status.
-	 * This approach takes care about the fragments: desc is the first
-	 * element in case of no SG.
-	 */
-	tx_q->tx_count_frames += nfrags + 1;
-	if (likely(priv->tx_coal_frames > tx_q->tx_count_frames) &&
-	    !(priv->synopsys_id >= DWMAC_CORE_4_00 &&
-	    (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) &&
-	    priv->hwts_tx_en)) {
-		stmmac_tx_timer_arm(priv, queue);
-	} else {
-		tx_q->tx_count_frames = 0;
-		stmmac_set_tx_ic(priv, desc);
-		priv->xstats.tx_set_ic_bit++;
-	}
-
 	if (priv->sarc_type)
 		stmmac_set_desc_sarc(priv, first, priv->sarc_type);
 
-- 
2.7.4