# \[PATCH AUTOSEL 4.19 56/68\] net: hisilicon: fix hip04-xmit never return TX\_BUSY - From: Sasha Levin \ - Date: 2019-08-14 02:18:03 - List: netdev - Page: https://ratatoskr.run/netdev/2019/08/5686928 - Thread: https://ratatoskr.run/stable/2019/08/5686901/t.md ```text From: Jiangfeng Xiao [ Upstream commit f2243b82785942be519016067ee6c55a063bbfe2 ] TX_DESC_NUM is 256, in tx_count, the maximum value of mod(TX_DESC_NUM - 1) is 254, the variable "count" in the hip04_mac_start_xmit function is never equal to (TX_DESC_NUM - 1), so hip04_mac_start_xmit never return NETDEV_TX_BUSY. tx_count is modified to mod(TX_DESC_NUM) so that the maximum value of tx_count can reach (TX_DESC_NUM - 1), then hip04_mac_start_xmit can reurn NETDEV_TX_BUSY. Signed-off-by: Jiangfeng Xiao Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/hisilicon/hip04_eth.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/hisilicon/hip04_eth.c b/drivers/net/ethernet/hisilicon/hip04_eth.c index 57c0afa25f9fb..fe3b1637fd5f4 100644 --- a/drivers/net/ethernet/hisilicon/hip04_eth.c +++ b/drivers/net/ethernet/hisilicon/hip04_eth.c @@ -185,7 +185,7 @@ struct hip04_priv { static inline unsigned int tx_count(unsigned int head, unsigned int tail) { - return (head - tail) % (TX_DESC_NUM - 1); + return (head - tail) % TX_DESC_NUM; } static void hip04_config_port(struct net_device *ndev, u32 speed, u32 duplex) -- 2.20.1 ```