MT7621 SoC Traffic Won't Flow on RGMII2 Bus/2nd GMAC

[Arınç ÜNAL]

On 23/01/2022 18:26, Andrew Lunn wrote:
> On Sun, Jan 23, 2022 at 11:33:04AM +0300, Arınç ÜNAL wrote:
>> Hey Deng,
>>
>> On 23/01/2022 09:51, DENG Qingfang wrote:
>>> Hi,
>>>
>>> Do you set the ethernet pinmux correctly?
>>>
>>> &ethernet {
>>>       pinctrl-names = "default";
>>>       pinctrl-0 = <&rgmii1_pins &rgmii2_pins &mdio_pins>;
>>> };
>>
>> This fixed it! We did have &rgmii2_pins on the gmac1 node (it was originally
>> on external_phy) so we never thought to investigate the pinctrl
>> configuration further! Turns out &rgmii2_pins needs to be defined on the
>> ethernet node instead.
> 
> PHYs are generally external, so pinmux on them makes no sense. PHYs in
> DT are not devices in the usual sense, so i don't think the driver
> core will handle pinmux for them, even if you did list them.
> 
> This could be interesting for the DT compliance checker. Ideally we
> want it to warn if it finds a pinmux configuration in a PHY node.

I don't see any warnings about it:

$ cpp -nostdinc -I include -I arch -undef -x assembler-with-cpp 
drivers/staging/mt7621-dts/mt7621.dtsi mt7621.dtsi.preprocessed
$ dtc -I dts -O dtb -p 0x1000 mt7621.dtsi.preprocessed -o mt7621.dtb
drivers/staging/mt7621-dts/mt7621.dtsi:28.21-33.4: Warning 
(unit_address_vs_reg): /cpuintc at 0: node has a unit name, but no reg property
drivers/staging/mt7621-dts/mt7621.dtsi:40.34-47.6: Warning 
(unit_address_vs_reg): /fixedregulator at 0: node has a unit name, but no 
reg property
drivers/staging/mt7621-dts/mt7621.dtsi:49.39-56.4: Warning 
(unit_address_vs_reg): /fixedregulator at 1: node has a unit name, but no 
reg property
drivers/staging/mt7621-dts/mt7621.dtsi:410.11-449.7: Warning 
(unit_address_vs_reg): /ethernet at 1e100000/mdio-bus/switch0 at 0/ports: node 
has a reg or ranges property, but no unit name
drivers/staging/mt7621-dts/mt7621.dtsi:28.21-33.4: Warning 
(unique_unit_address): /cpuintc at 0: duplicate unit-address (also used in 
node /fixedregulator at 0)

> 
> It also sounds like you had them somewhere else wrong?

Yes, it was under the phy_external node:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/staging/mt7621-dts/mt7621.dtsi#n350

I had put it under gmac1 node instead since we didn't enable the 
phy_external node.

Arınç