Switch Port QoS to WLC

We have a Catalyst L3 Switch C9300-48P GigabitEthernet1/0/9 connecting to WLC AIR-CT5520-K9. We have lots of Total Output drops in millions over last 3 weeks. But there are 0 output errors. Current Queueing strategy is fifo. What would be the best queuing strategy for this port. Or Should I just try an ether channel to increase the bandwidth between?

GigabitEthernet1/0/9 is up, line protocol is up (connected) Hardware is Gigabit Ethernet, address is d4ad.bd2d.4c09 (bia d4ad.bd2d.4c09) MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec, reliability 255/255, txload 55/255, rxload 57/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX input flow-control is on, output flow-control is unsupported ARP type: ARPA, ARP Timeout 04:00:00 Last input never, output 00:00:01, output hang never Last clearing of "show interface" counters never Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 280748031 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 226549000 bits/sec, 46950 packets/sec 5 minute output rate 217600000 bits/sec, 42123 packets/sec 19713046898 packets input, 11814567797426 bytes, 0 no buffer Received 14286820 broadcasts (11317565 multicasts) 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 11317565 multicast, 0 pause input 0 input packets with dribble condition detected 16347560425 packets output, 11315695952318 bytes, 0 underruns 0 output errors, 0 collisions, 2 interface resets 0 unknown protocol drops 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier, 0 pause output 0 output buffer failures, 0 output buffers swapped out 

Thanks in advance.