# Re: \[RFC net-next 2/2\] net: fec: add ndo\_select\_queue to fix TX bandwidth fluctuations

- From: Andrew Lunn \<andrew@lunn.ch\>
- Date: 2021-05-23 14:46:21 
- List: netdev
- Page: https://ratatoskr.run/netdev/2021/05/1388679
- Thread: https://ratatoskr.run/netdev/2021/05/1388643/t.md

```text
On Sun, May 23, 2021 at 06:20:19PM +0800, Joakim Zhang wrote:
> From: Fugang Duan <redacted>
> 
> As we know that AVB is enabled by default, and the ENET IP design is
> queue 0 for best effort, queue 1&2 for AVB Class A&B. Bandwidth of
> queue 1&2 set in driver is 50%, TX bandwidth fluctuated when selecting
> tx queues randomly with FEC_QUIRK_HAS_AVB quirk available.

How is the driver currently scheduling between these queues? Given the
802.1q priorities, i think we want queue 2 with the highest priority
for scheduling. Then queue 0 and lastly queue 1.

    Andrew
```