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Date:   Sun, 23 May 2021 16:46:12 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Joakim Zhang <qiangqing.zhang@nxp.com>
Cc:     davem@davemloft.net, kuba@kernel.org, frieder.schrempf@kontron.de,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-imx@nxp.com
Subject: Re: [RFC net-next 2/2] net: fec: add ndo_select_queue to fix TX
 bandwidth fluctuations
Message-ID: <YKpqtK7YBVFnqRSw@lunn.ch>
References: <20210523102019.29440-1-qiangqing.zhang@nxp.com>
 <20210523102019.29440-3-qiangqing.zhang@nxp.com>
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On Sun, May 23, 2021 at 06:20:19PM +0800, Joakim Zhang wrote:
> From: Fugang Duan <fugang.duan@nxp.com>
> 
> 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