[U-Boot] [PATCH v2 2/5] net: sun8i_emac: Support RX/TX delay chains

[Joe Hershberger]

On Wed, Dec 6, 2017 at 8:35 PM, Chen-Yu Tsai <wens at csie.org> wrote:
> On Thu, Dec 7, 2017 at 4:20 AM, Joe Hershberger
> <joe.hershberger at gmail.com> wrote:
>> On Tue, Dec 5, 2017 at 8:34 PM, Chen-Yu Tsai <wens at csie.org> wrote:
>>> On Wed, Dec 6, 2017 at 4:50 AM, Joe Hershberger <joe.hershberger at ni.com> wrote:
>>>> On Fri, Nov 24, 2017 at 11:08 PM, Chen-Yu Tsai <wens at csie.org> wrote:
>>>>> The EMAC syscon has configurable RX/TX delay chains for use with RGMII
>>>>> PHYs.
>>>>>
>>>>> This adds support for configuring them via device tree properties. The
>>>>> property names and format were defined in Linux's dwmac-sun8i binding
>>>>> that was merged at one point.
>>>>
>>>> I'm not seeing this in doc/device-tree-bindings/net/
>>>
>>> See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
>>>
>>> The bindings have been restored as of v4.15-rc1.
>>>
>>> We are following DT bindings as defined in the Linux kernel. Deviation
>>> is kept to a minimum, and eliminated if possible. We still need to
>>> migrate the driver to the new bindings for the internal PHY bits.
>>> But that bit might still be changed during the 4.15 release cycle.
>>
>> That's good, but we want to have the currently supported bindings
>> copied into the U-Boot tree under doc/device-tree-bindings/net/.
>> Please include a patch that adds the bindings that your driver is
>> using.
>
> Looks like this is a new requirement. Or it wasn't really enforced
> before. Doesn't this make U-boot prone to having diverging device
> tree bindings? It has already happened with the regulator bindings,
> specifically the "regulator-name" property.
>
> And by "currently supported", are you referring to what the driver
> expects, and not what the end result, i.e. the accepted bindings
> in Linux, should be? This driver is still in a state of catchup.
> The driver supports a previously merged then reverted set of
> bindings. These bindings were then brought back and updated for
> Linux v4.15 (unreleased yet, so may still change, again). So which
> set of bindings should I submit here?
>
> And the goal _is_ to migrate the driver to what Linux is using, so
> we can share the device tree files.

I believe the goal is to have them match the current state of the
driver as supported in U-Boot, and a higher-level goal of keeping the
bindings + driver in sync with Linux for sharing.

Correct, Simon?

Thanks,
-Joe