Hi Dan,
On 8/21/2025 6:02 PM, Dan Carpenter wrote:
Hello Vineeth Karumanchi,
Commit 89934dbf169e ("net: macb: Add TAPRIO traffic scheduling
support") from Aug 14, 2025 (linux-next), leads to the following
Smatch static checker warning:
drivers/net/ethernet/cadence/macb_main.c:4107 macb_taprio_setup_replace()
warn: unsigned 'start_time' is never less than zero.
drivers/net/ethernet/cadence/macb_main.c
4088 static int macb_taprio_setup_replace(struct net_device *ndev,
4089 struct tc_taprio_qopt_offload *conf)
4090 {
4091 u64 total_on_time = 0, start_time_sec = 0, start_time = conf->base_time;
^^^ ^^^^^^^^^^
start_time is unsigned
4092 u32 configured_queues = 0, speed = 0, start_time_nsec;
4093 struct macb_queue_enst_config *enst_queue;
4094 struct tc_taprio_sched_entry *entry;
4095 struct macb *bp = netdev_priv(ndev);
4096 struct ethtool_link_ksettings kset;
4097 struct macb_queue *queue;
4098 size_t i;
4099 int err;
4100
4101 if (conf->num_entries > bp->num_queues) {
4102 netdev_err(ndev, "Too many TAPRIO entries: %zu > %d queues\n",
4103 conf->num_entries, bp->num_queues);
4104 return -EINVAL;
4105 }
4106
--> 4107 if (start_time < 0) {
^^^^^^^^^^^^^^
Delete this impossible check?
I'll examine it and submit the patch.
4108 netdev_err(ndev, "Invalid base_time: must be 0 or positive, got %lld\n",
4109 conf->base_time);
4110 return -ERANGE;
4111 }
4112
4113 /* Get the current link speed */
regards,
dan carpenter
Thanks,
--
🙏 Vineeth
