Re: [PATCH net v2] net: Always descend into dsa/ folder with CONFIG_NET_DSA enabled

[Vladimir Oltean <olteanv@gmail.com>]

On Thu, May 16, 2024 at 09:56:30AM -0700, Florian Fainelli wrote:
> Stephen reported that he was unable to get the dsa_loop driver to get
> probed, and the reason ended up being because he had CONFIG_FIXED_PHY=y
> in his kernel configuration. As Masahiro explained it:
> 
>   "obj-m += dsa/" means everything under dsa/ must be modular.
> 
>   If there is a built-in object under dsa/ with CONFIG_NET_DSA=m,
>   you cannot do  "obj-$(CONFIG_NET_DSA) += dsa/".
> 
>   You need to change it back to "obj-y += dsa/".
> 
> This was the case here whereby CONFIG_NET_DSA=m, and so the
> obj-$(CONFIG_FIXED_PHY) += dsa_loop_bdinfo.o rule is not executed and
> the DSA loop mdio_board info structure is not registered with the
> kernel, and eventually the device is simply not found.
> 
> To preserve the intention of the original commit of limiting the amount
> of folder descending, conditionally descend into drivers/net/dsa when
> CONFIG_NET_DSA is enabled.
> 
> Fixes: 227d72063fcc ("dsa: simplify Kconfig symbols and dependencies")
> Reported-by: Stephen Langstaff <stephenlangstaff1@gmail.com>
> Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
> ---

Reviewed-by: Vladimir Oltean <olteanv@gmail.com>