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

[Yao Zi]

On Fri, Sep 18, 2026 at 02:48:45PM +0800, Tiezhu Yang wrote:
> On 2026/9/17 下午10:45, Andrew Lunn wrote:
> > > 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?
> 
> If it is not proper to change Kconfig,
> I am fine to modify the arch-specific defconfig instead.

I'm against both of the ideas. From the aspect of a distribution
maintainer, there are too many stuff missing from architecture
defconfigs, so only enabling one or two drivers by default doesn't even
improve the situation much, costs (kernel) maintainers' time.

>From the aspect of a kernel developer, a bloated defconfig/default only
further lengthen the compilation process, forcing ones that don't have a
good enough machine to spend more time on turning off one and another
options their platforms don't need.

> But by the way, I noticed that there are the following code:
> 
> $ grep -rnw "default m" drivers/net/ethernet/
> drivers/net/ethernet/stmicro/stmmac/Kconfig:221:	default m if ARCH_SOPHGO
> drivers/net/ethernet/stmicro/stmmac/Kconfig:233:	default m if ARCH_SPACEMIT
> drivers/net/ethernet/stmicro/stmmac/Kconfig:245:	default m if ARCH_STARFIVE
> drivers/net/ethernet/spacemit/Kconfig:21:	default m if ARCH_SPACEMIT
> drivers/net/ethernet/marvell/octeontx2/Kconfig:54:	default m
> drivers/net/ethernet/hisilicon/Kconfig:106:	default m
> drivers/net/ethernet/hisilicon/Kconfig:134:	default m
> drivers/net/ethernet/sun/Kconfig:77:	default m
> drivers/net/ethernet/sun/Kconfig:81:	default m
> drivers/net/ethernet/sun/Kconfig:89:	default m
> drivers/net/ethernet/mellanox/mlxsw/Kconfig:37:	default m
> drivers/net/ethernet/mellanox/mlxsw/Kconfig:47:	default m
> drivers/net/ethernet/mellanox/mlxsw/Kconfig:67:	default m
> drivers/net/ethernet/mellanox/mlxsw/Kconfig:86:	default m
> 
> Thanks,
> Tiezhu
> 

Best regards,
Yao Zi