Hi! On Fri, Sep 21, 2018 at 12:25:53PM -0300, Rodrigo Exterckötter Tjäder wrote: > 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 Exterckötter Tjäder wrote: > > > Without "allwinner,tx-delay-ps = <600>;" on the DTP it can receive packets > > > but not send. > > > > > > Signed-off-by: Rodrigo Exterckötter Tjäder <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 Exterckötter Tjäder <rodrigo@xxxxxxxxxx> There's no need to be so specific though :) Something like that would work: arm64: dts: allwinner: a64-olinuxino: set the PHY TX delay The PHY found on the A64-Olinuxino requires a TX delay in order to operate properly. Olimex uses a 600ps second delay in their BSP, and that has been found to work, so let's use that value in the current DT. Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
