net/mlx4_en: Resolve dividing by zero in 32-bit system

[cascardo/linux.git] / drivers / net / ethernet / mellanox / mlx4 / en_clock.c

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_clock.c b/drivers/net/ethernet/mellanox/mlx4/en_clock.c
index 1494997..a5fc46b 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/en_clock.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_clock.c
@@ -245,8 +245,11 @@ static u32 freq_to_shift(u16 freq)
 {
        u32 freq_khz = freq * 1000;
        u64 max_val_cycles = freq_khz * 1000 * MLX4_EN_WRAP_AROUND_SEC;
+       u64 tmp_rounded =
+               roundup_pow_of_two(max_val_cycles) > max_val_cycles ?
+               roundup_pow_of_two(max_val_cycles) - 1 : UINT_MAX;
        u64 max_val_cycles_rounded = is_power_of_2(max_val_cycles + 1) ?
-               max_val_cycles : roundup_pow_of_two(max_val_cycles) - 1;
+               max_val_cycles : tmp_rounded;
        /* calculate max possible multiplier in order to fit in 64bit */
        u64 max_mul = div_u64(0xffffffffffffffffULL, max_val_cycles_rounded);
 
@@ -298,7 +301,7 @@ void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev)
        if (IS_ERR(mdev->ptp_clock)) {
                mdev->ptp_clock = NULL;
                mlx4_err(mdev, "ptp_clock_register failed\n");
-       } else {
+       } else if (mdev->ptp_clock) {
                mlx4_info(mdev, "registered PHC clock\n");
        }