Re: [PATCH 2/2] arm64: dts: allwinner: Olimex A64-OLinuXino: fix ethernet

From: Rodrigo ExterckÃtter TjÃder
Date: Fri Sep 21 2018 - 11:26:09 EST

On Fri, Sep 21, 2018 at 11:30 AM Maxime Ripard
<maxime.ripard@xxxxxxxxxxx> wrote:
> On Wed, Sep 19, 2018 at 11:19:36AM -0300, Rodrigo ExterckÃtter TjÃder wrote:
> > Without "allwinner,tx-delay-ps = <600>;" on the DTP it can receive packets
> > but not send.
> >
> > Signed-off-by: Rodrigo ExterckÃtter TjÃder <rodrigo@xxxxxxxxxx>
> Again, that commit log would be nice if it was a bit more
> explicit. What is a DTP? How did you come up with that value? What is
> the value used by Allwinner/Olimex, and why did you use another one if
> you did?

Thanks for the feedback.

DTP is a typo, it should have been DT for "device tree".

Olimex's provided device tree uses a different driver for ethernet,
but it has a property named "tx-delay" with value 6 and the range of
the property is 0-7. On dwmac-sun8i's bindings documentation it says
allwinner,tx-delay-ps has a range of 0-700 and must be a multiple of
100, so I tried 600 and it works.

I'm not sure how much of that I should include in the commit log,
perhaps something like this:

arm64: dts: allwinner: OLinuXino: PHY TX clock delay

The PHY requres a delay on the TX clock, otherwise it is not able to send
any packets on the interface.

Olimex's device tree uses 6 in a range of 0-7, dwmac-sun8i requires a
multiple of 100 in the range 0-700.

Signed-off-by: Rodrigo ExterckÃtter TjÃder <rodrigo@xxxxxxxxxx>