[EXT] Re: (EXT) [PATCH v3] arm64: dts: imx8mp-evk: configure multiple queues on eqos

[Xiaoliang Yang]

On Thu, 16 Dec 2021 18:07:13 Alexander Stein wrote:
> > Eqos ethernet support five queues on hardware, enable these queues and
> > configure the priority of each queue. Uses Strict Priority as
> > scheduling algorithms to ensure that the TSN function works.
> >
> > The priority of each queue is a bitmask value that maps VLAN tag
> > priority to the queue. Since the hardware only supports five queues,
> > this patch maps priority 0-4 to queues one by one, and priority 5-7 to
> > queue 4.
> >
> > The total fifo size of 5 queues is 8192 bytes, if enable 5 queues with
> > store-and-forward mode, it's not enough for large packets, which would
> > trigger fifo overflow frequently. This patch set DMA to thresh mode to
> > enable all 5 queues.
> 
> Is there a specific reason to configure this only on board-level but not for all
> imx8mp in general?
How many queues are enabled and what attributes are set to eqos depends on the needs of users. Different boards may have different requirements. For example, we set the threshold mode and 5 queues on the imx8mp-evk board, but other boards may also require SF mode and 3 queues. We set up 5 queues and SP scheduling modes on the i.mx9mp-evk board to better use the TSN function.

Thanks,
Xiaoliang