When the network port is down, the queue is released, and ring->len is 0. In debugfs, hbg_get_queue_used_num() will be called, which may lead to a division by zero issue. This patch adds a check, if ring->len is 0, hbg_get_queue_used_num() directly returns 0. Fixes: 40735e7543f9 ("net: hibmcge: Implement .ndo_start_xmit function") Signed-off-by: Jijie Shao Reviewed-by: Simon Horman --- drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.h b/drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.h index 2883a5899ae2..2aecc73f3d49 100644 --- a/drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.h +++ b/drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.h @@ -29,6 +29,9 @@ static inline bool hbg_fifo_is_full(struct hbg_priv *priv, enum hbg_dir dir) static inline u32 hbg_get_queue_used_num(struct hbg_ring *ring) { + if (!ring->len) + return 0; + return (ring->ntu + ring->len - ring->ntc) % ring->len; } -- 2.33.0