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

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

[Tiezhu Yang]

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
-- 
2.42.0

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

[Yao Zi]

On Tue, Sep 15, 2026 at 03:32:06PM +0800, 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.

YT6801 isn't a Loongson-specific peripheral, it's already shipped in
many other PCIe addon cards, and some x86 laptops iirc, thus it just
seems wrong to do this in the driver's Kconfig entry. I would NAK this
patch.

> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>

Best regards,
Yao Zi

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

[Maxime Chevallier]

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.

Maxime

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

[Tiezhu Yang]

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

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

[Andrew Lunn]

> 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.

~/linux/drivers/net/ethernet/stmicro/stmmac$ grep default Kconfig
	default n
	default y
	default STMMAC_PLATFORM
	default ARC
	default MACH_INGENIC
	default ARCH_QCOM
	default ARCH_LPC18XX
	default ARCH_MESON
	default ARCH_MA35
	default ARCH_QCOM
	default ARCH_RENESAS
	default ARCH_ROCKCHIP
	default ARCH_RZN1
	default ARCH_S32
	default ARCH_INTEL_SOCFPGA
	default m if ARCH_SOPHGO
	default m if ARCH_SPACEMIT
	default m if ARCH_STARFIVE
	default ARCH_STI
	default ARCH_STM32
	default ARCH_SUNXI
	default ARCH_SUNXI
	default ARCH_SUNXI
	default ARCH_MXC
	default MACH_LOONGSON32
	default ARCH_VISCONTI
	default X86
	default MACH_LOONGSON64

No other glue driver does this. Why is this one special?

   Andrew