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

[Jose Abreu]

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 <joab...@synopsys.com>

---
Cc: Giuseppe Cavallaro <peppe.cavall...@st.com>
Cc: Alexandre Torgue <alexandre.tor...@st.com>
Cc: Jose Abreu <joab...@synopsys.com>
Cc: "David S. Miller" <da...@davemloft.net>
Cc: Maxime Coquelin <mcoquelin.st...@gmail.com>
Cc: net...@vger.kernel.org
Cc: linux-st...@st-md-mailman.stormreply.com
Cc: linux-arm-ker...@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