[U-Boot] [PATCH 09/10] net: mvpp2x: remove TX drain from transmit routine

[stefanc at malvell.com]

From: Stefan Chulski <stefanc at marvell.com>

TX drain in transmit procedure could cause issues due
to race between drain procedure and transmition of descriptor
between AGGR TXQ and physical TXQ.
TXQ be cleared before moving to Linux by stop procedure.

Change-Id: I1d52cf087505d35d8a10e0249f78d0177a569658
Signed-off-by: Stefan Chulski <stefanc at marvell.com>
Reviewed-on: http://vgitil04.il.marvell.com:8080/39968
Tested-by: iSoC Platform CI <ykjenk at marvell.com>
Reviewed-by: Nadav Haklai <nadavh at marvell.com>
Reviewed-on: http://vgitil04.il.marvell.com:8080/39955
Reviewed-by: Igal Liberman <igall at marvell.com>
---
 drivers/net/mvpp2.c | 21 ---------------------
 1 file changed, 21 deletions(-)

diff --git a/drivers/net/mvpp2.c b/drivers/net/mvpp2.c
index 931047e..8168539 100644
--- a/drivers/net/mvpp2.c
+++ b/drivers/net/mvpp2.c
@@ -5261,21 +5261,6 @@ static int mvpp2_recv(struct udevice *dev, int flags, uchar **packetp)
 	return rx_bytes;
 }
 
-/* Drain Txq */
-static void mvpp2_txq_drain(struct mvpp2_port *port, struct mvpp2_tx_queue *txq,
-			    int enable)
-{
-	u32 val;
-
-	mvpp2_write(port->priv, MVPP2_TXQ_NUM_REG, txq->id);
-	val = mvpp2_read(port->priv, MVPP2_TXQ_PREF_BUF_REG);
-	if (enable)
-		val |= MVPP2_TXQ_DRAIN_EN_MASK;
-	else
-		val &= ~MVPP2_TXQ_DRAIN_EN_MASK;
-	mvpp2_write(port->priv, MVPP2_TXQ_PREF_BUF_REG, val);
-}
-
 static int mvpp2_send(struct udevice *dev, void *packet, int length)
 {
 	struct mvpp2_port *port = dev_get_priv(dev);
@@ -5319,9 +5304,6 @@ static int mvpp2_send(struct udevice *dev, void *packet, int length)
 		tx_done = mvpp2_txq_pend_desc_num_get(port, txq);
 	} while (tx_done);
 
-	/* Enable TXQ drain */
-	mvpp2_txq_drain(port, txq, 1);
-
 	timeout = 0;
 	do {
 		if (timeout++ > 10000) {
@@ -5331,9 +5313,6 @@ static int mvpp2_send(struct udevice *dev, void *packet, int length)
 		tx_done = mvpp2_txq_sent_desc_proc(port, txq);
 	} while (!tx_done);
 
-	/* Disable TXQ drain */
-	mvpp2_txq_drain(port, txq, 0);
-
 	return 0;
 }
 
-- 
1.9.1