Re: [PATCH net-next v1] net: stmmac: Default DWMAC_MOTORCOMM to m on MACH_LOONGSON64

[Tiezhu Yang <yangtiezhu@loongson.cn>]

On 2026/9/17 上午12:54, Maxime Chevallier wrote:
> Hi
> 
> On 9/15/26 09:32, Tiezhu Yang wrote:
>> Currently, there is no network connectivity when upgrading to the
>> latest upstream mainline kernel on certain Loongson machines such
>> as Loongson-3C6000 server, because the driver for the onboard NIC
>> is not enabled.
>>
>> Enable the Motorcomm PCI DWMAC driver as a module by default when
>> building for the Loongson-64 platform.
>>
>> This ensures out-of-the-box support for Motorcomm YT6801 Ethernet
>> controllers on Loongson machines, enabling demand-loading without
>> increasing the core kernel image size.
>>
>> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
>> ---
>>   drivers/net/ethernet/stmicro/stmmac/Kconfig | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
>> index ab3c4cf96423..c86d6c08977c 100644
>> --- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
>> +++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
>> @@ -408,6 +408,7 @@ config DWMAC_LOONGSON
>>   
>>   config DWMAC_MOTORCOMM
>>   	tristate "Motorcomm PCI DWMAC support"
>> +	default m if MACH_LOONGSON64
>>   	depends on PCI
>>   	select MOTORCOMM_PHY
>>   	select STMMAC_LIBPCI
> 
> I agree with Yao Zi, this belongs in your .config, maybe your
> defconfig, but not in the stmmac Kconfig.

Thanks for the constructive suggestions.

Before moving forward, I'd like to share an alternative thought.
As noted in the earlier review, this network controller could be
used across multiple architectures. To avoid the redundant churn
in the defconfigs of every single architecture, I am wondering if
we could unconditionally set it to default m in the Kconfig instead.

Please let me know whether it makes sense:

```
diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig 
b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index ab3c4cf96423..bea18cb4b697 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -408,6 +408,7 @@ config DWMAC_LOONGSON

  config DWMAC_MOTORCOMM
         tristate "Motorcomm PCI DWMAC support"
+       default m
         depends on PCI
         select MOTORCOMM_PHY
         select STMMAC_LIBPCI
```

If no, I will modify the arch-specific config.

Thanks,
Tiezhu