fix: taprio: Change type of txtime-delay parameter to u32

During the review of the iproute2 patches for txtime-assist mode, it was
pointed out that it does not make sense for the txtime-delay parameter to
be negative. So, change the type of the parameter from s32 to u32.

Fixes: 4cfd5779 ("taprio: Add support for txtime-assist mode")
Reported-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NVedang Patel <vedang.patel@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/uapi/linux/pkt_sched.h

@@ -1174,7 +1174,7 @@ enum {
 	TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME, /* s64 */
 	TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION, /* s64 */
 	TCA_TAPRIO_ATTR_FLAGS, /* u32 */
-	TCA_TAPRIO_ATTR_TXTIME_DELAY, /* s32 */
+	TCA_TAPRIO_ATTR_TXTIME_DELAY, /* u32 */
 	__TCA_TAPRIO_ATTR_MAX,
 };
 

net/sched/sch_taprio.c

@@ -75,7 +75,7 @@ struct taprio_sched {
 	struct sched_gate_list __rcu *admin_sched;
 	struct hrtimer advance_timer;
 	struct list_head taprio_list;
-	int txtime_delay;
+	u32 txtime_delay;
 };
 
 static ktime_t sched_base_time(const struct sched_gate_list *sched)
@@ -1113,7 +1113,7 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
 			goto unlock;
 		}
 
-		q->txtime_delay = nla_get_s32(tb[TCA_TAPRIO_ATTR_TXTIME_DELAY]);
+		q->txtime_delay = nla_get_u32(tb[TCA_TAPRIO_ATTR_TXTIME_DELAY]);
 	}
 
 	if (!TXTIME_ASSIST_IS_ENABLED(taprio_flags) &&
@@ -1430,7 +1430,7 @@ static int taprio_dump(struct Qdisc *sch, struct sk_buff *skb)
 		goto options_error;
 
 	if (q->txtime_delay &&
-	    nla_put_s32(skb, TCA_TAPRIO_ATTR_TXTIME_DELAY, q->txtime_delay))
+	    nla_put_u32(skb, TCA_TAPRIO_ATTR_TXTIME_DELAY, q->txtime_delay))
 		goto options_error;
 
 	if (oper && dump_schedule(skb, oper))