Re: [PATCH net-next 0/4] net: phy: mscc-miim: reduce waiting time between MDIO transactions

Antoine Tenart
2020-05-27T07:01:04Z

Hi Andrew,

Quoting Andrew Lunn (2020-05-26 19:01:00)
> On Tue, May 26, 2020 at 06:22:52PM +0200, Antoine Tenart wrote:
> >
> > This series aims at reducing the waiting time between MDIO transactions
> > when using the MSCC MIIM MDIO controller.
>
> There are a couple of other things you can look at:
>
> Can you disable the pre-amble on the MDIO transaction. It requires
> that both the bus master and all devices on the bus support it, but
> when it is usable, you half the number of bits sent over the wire.
>
> Can you control the frequency of MDC? 802.3 says 2.5MHz, but many
> devices support higher speeds. Again, you need all devices on the bus
> to support the speed.
>
> When accessing raw TDR data for cable tests i also have a lot of PHY
> accesses. I implemented both of these for the FEC MDIO bus, and made
> it a lot faster.

Thanks for the tips!

Antoine

--
Antoine Ténart, Bootlin
Embedded Linux and Kernel engineering