[PATCH 1/3] net: give a different name to rtl8169 interfaces

[Quentin Schulz]

Hi Etienne,

On 6/25/24 8:38 AM, Etienne Dublé wrote:
> Hi Quentin,
> 
> Thanks for reviewing my patches.
> 
> Le 24/06/2024 à 15:08, Quentin Schulz a écrit :
>> [...]
>>
>>>   1 file changed, 11 insertions(+)
>>>
>>> diff --git a/drivers/net/rtl8169.c b/drivers/net/rtl8169.c
>>> index 93e83661ce..b30d51731f 100644
>>> --- a/drivers/net/rtl8169.c
>>> +++ b/drivers/net/rtl8169.c
>>> @@ -1091,6 +1091,16 @@ static int rtl8169_eth_probe(struct udevice *dev)
>>>       return 0;
>>>   }
>>>   +static int rtl8169_eth_bind(struct udevice *dev)
>>> +{
>>> +    static int card_number;
>>> +    char name[16];
>>> +
>>> +    sprintf(name, "RTL8169#%u", card_number++);
>>> +
>>> +    return device_set_name(dev, name);
>>> +}
>>> +
>>
>> I don't think we can guarantee bind order so this may not be stable 
>> over time.
>>
>> I'm wondering if there isn't a way to use the "ethernet" (ethernet0, 
>> ethernet1) alias in DT instead?
> 
> Actually the ethernet interfaces are not declared in the device tree, 
> only PCI buses are (at least on this Nanopi board).
> The ethernet interfaces are only detected when running "pci enum".
> 

Ah shoot.

> Another option may be to name them "rtl8169@<hexa>", with "<hexa>" 
> reflecting the PCI region address (so it is unique and stable). What do 
> you think?
> 

I guess that's one way, I'm also wondering how systemd renames those to 
be unique but stable on the same machine, maybe we could take some 
inspiration from them for that?

FYI, for NVMEs I also have 
/dev/disk/by-path/platform-fe190000.pcie-pci-0004:41:00.0-nvme-1 for 
example. platform-fe19000.pcie- being the pcie controller at address 
fe19000 on the platform root bus, no clue about what's after that 
though. I also assume the N in nvme-N isn't necessarily stable over time 
but whatever's before should be? Maybe there's something like 
ports/addresses on the PCIe bus that will never change or rely on probe 
order/timings to keep a stable naming?
Sorry, don't know much about PCIe so cannot suggest anything meaningful :/

Cheers,
Quentin