[PATCH net-next 1/6] net: stmmac: Prevent divide-by-zero

When RX Coalesce settings are set to all zero (which is a valid setting)
we will currently get a divide-by-zero error. Fix it.

Signed-off-by: Jose Abreu <redacted>

---
Cc: Giuseppe Cavallaro <redacted>
Cc: Alexandre Torgue <redacted>
Cc: Jose Abreu <redacted>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: netdev@vger.kernel.org
Cc: linux-stm32@st-md-mailman.stormreply.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 686b82068142..6e44013b20cc 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -3418,7 +3418,9 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv, u32 queue)
 		stmmac_refill_desc3(priv, rx_q, p);
 
 		rx_q->rx_count_frames++;
-		rx_q->rx_count_frames %= priv->rx_coal_frames;
+		rx_q->rx_count_frames += priv->rx_coal_frames;
+		if (rx_q->rx_count_frames > priv->rx_coal_frames)
+			rx_q->rx_count_frames = 0;
 		use_rx_wd = priv->use_riwt && rx_q->rx_count_frames;
 
 		dma_wmb();

-- 
2.7.4