[PATCH RFC 3/5] net:stmmac: ensure we reclaim all dirty descriptors.

[Jimmy Perchet <jimmy.perchet@parrot.com>]

On low speed link (10MBit/s), some TX descriptors can remain dirty
if the tx coalescence timer expires before they were treated. Re-arm timer
in this case.

Signed-off-by: Jimmy Perchet <jimmy.perchet@parrot.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 0015175..af04b5d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1284,8 +1284,12 @@ static void stmmac_tx_clean(struct stmmac_priv *priv)
 			p = priv->dma_tx + entry;
 
 		/* Check if the descriptor is owned by the DMA. */
-		if (priv->hw->desc->get_tx_owner(p))
+		if (priv->hw->desc->get_tx_owner(p)) {
+			/* Be sure to harvest remaining descriptor. */
+			mod_timer(&priv->txtimer,
+			  STMMAC_COAL_TIMER(priv->tx_coal_timer));
 			break;
+		}
 
 		/* Verify tx error by looking at the last segment. */
 		last = priv->hw->desc->get_tx_ls(p);
-- 
1.8.1.2