net: ethernet: renesas: ravb_main: test clock rate to avoid division by 0

The clk API may return 0 on clk_get_rate, so we should check the result before
using it as a divisor.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 087e14a..9e2a0bd 100644 (file)
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1691,6 +1691,9 @@ static int ravb_set_gti(struct net_device *ndev)
        rate = clk_get_rate(clk);
        clk_put(clk);
 
+       if (!rate)
+               return -EINVAL;
+
        inc = 1000000000ULL << 20;
        do_div(inc, rate);