[U-Boot] [PATCH] arm: dts: Pine64: add Ethernet alias

[Hans de Goede]

Hi,

On 26-10-16 09:00, Jagan Teki wrote:
> On Tue, Oct 25, 2016 at 3:59 AM, André Przywara <andre.przywara at arm.com> wrote:
>> On 21/10/16 11:28, Hans de Goede wrote:
>>> Hi,
>>>
>>> On 21-10-16 12:06, Andre Przywara wrote:
>>>> Hi,
>>>>
>>>> On 21/10/16 10:31, Jagan Teki wrote:
>>>>> On Fri, Oct 21, 2016 at 5:41 AM, Andre Przywara
>>>>> <andre.przywara at arm.com> wrote:
>>>>>> The sun8i-emac driver works fine with the A64 Ethernet IP, but we are
>>>>>> missing an alias entry to trigger the driver instantiation by U-Boot.
>>>>>> Add the line to point U-Boot to the Ethernet DT node.
>>>>>> This enables TFTP boot on the Pine64.
>>>>>>
>>>>>> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
>>>>>> ---
>>>>>>  arch/arm/dts/sun50i-a64-pine64-common.dtsi | 1 +
>>>>>>  1 file changed, 1 insertion(+)
>>>>>>
>>>>>> diff --git a/arch/arm/dts/sun50i-a64-pine64-common.dtsi
>>>>>> b/arch/arm/dts/sun50i-a64-pine64-common.dtsi
>>>>>> index d5a7249..c0fde44 100644
>>>>>> --- a/arch/arm/dts/sun50i-a64-pine64-common.dtsi
>>>>>> +++ b/arch/arm/dts/sun50i-a64-pine64-common.dtsi
>>>>>> @@ -46,6 +46,7 @@
>>>>>>
>>>>>>         aliases {
>>>>>>                 serial0 = &uart0;
>>>>>> +               ethernet0 = &emac;
>>>>>
>>>>> I think alias doesn’t require for probing emac, it will straight away
>>>>> probed like
>>>>>
>>>>>> dm tree
>>>>> ....
>>>>> eth         [ + ]     ethernet at 01c30000
>>>>>
>>>>> Did you find any issue while detecting eth?
>>>>
>>>> Yes, it just didn't work ;-) I don't have a board here, but can post the
>>>> error message later tonight.
>>
>> ....
>> Net:   phy interface7
>>
>> Error: ethernet at 01c30000 address not set.
>> No ethernet found.
>> ....
>>
>>>> In fact I was wondering about that already, maybe it's worth
>>>> investigating this further.
>>
>> So the reason is that CONFIG_NET_RANDOM_ETHADDR isn't defined, so
>> without the DT alias triggering the SID MAC generation there will be
>> _no_ MAC address at all, which makes the driver give up.
>> AFAIK on the A64 the MAC generation from the SID serial number works
>> just fine, so we should in any case add the alias.
>
> I wondered how the alias related to MAC generation,

See the setup_environment() function in board/sunxi/board.c, we use
the alias-es to determine for which interface we need to generate
a random MAC and set ethaddr / eth1addr in the environment.

Regards,

Hans