[U-Boot] [PATCH] net: cpsw: ti: Reap completed packets before stopping interface

[Alex Kiernan]

If you send a final packet just before stopping the interface (e.g. a final
ACK as part of the UDP fastboot protocol), then that packet isn't reliably
delivered onto the wire.

Reap packets prior to stopping the interface to ensure any which are
in-flight make it out. Also remove buffer and len from the call to
cpdma_process() as we weren't using them on their return.

Signed-off-by: Alex Kiernan <alex.kiernan at gmail.com>
---

 drivers/net/cpsw.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/drivers/net/cpsw.c b/drivers/net/cpsw.c
index e2395db..9919d39 100644
--- a/drivers/net/cpsw.c
+++ b/drivers/net/cpsw.c
@@ -910,8 +910,22 @@ out:
 	return ret;
 }
 
+static int cpsw_reap_completed_packets(struct cpsw_priv *priv)
+{
+	int timeout = CPDMA_TIMEOUT;
+
+	/* reap completed packets */
+	while (timeout-- &&
+	       (cpdma_process(priv, &priv->tx_chan, NULL, NULL) >= 0))
+		;
+
+	return timeout;
+}
+
 static void _cpsw_halt(struct cpsw_priv *priv)
 {
+	cpsw_reap_completed_packets(priv);
+
 	writel(0, priv->dma_regs + CPDMA_TXCONTROL);
 	writel(0, priv->dma_regs + CPDMA_RXCONTROL);
 
@@ -925,18 +939,12 @@ static void _cpsw_halt(struct cpsw_priv *priv)
 
 static int _cpsw_send(struct cpsw_priv *priv, void *packet, int length)
 {
-	void *buffer;
-	int len;
-	int timeout = CPDMA_TIMEOUT;
+	int timeout;
 
 	flush_dcache_range((unsigned long)packet,
 			   (unsigned long)packet + ALIGN(length, PKTALIGN));
 
-	/* first reap completed packets */
-	while (timeout-- &&
-		(cpdma_process(priv, &priv->tx_chan, &buffer, &len) >= 0))
-		;
-
+	timeout = cpsw_reap_completed_packets(priv);
 	if (timeout == -1) {
 		printf("cpdma_process timeout\n");
 		return -ETIMEDOUT;
-- 
2.7.4