On Fri, 6 Oct 2023 12:31:59 +0200
Greg KH [off-list ref] wrote:

On Fri, Oct 06, 2023 at 06:49:11PM +0900, FUJITA Tomonori wrote:

quoted

+config AX88796B_RUST_PHY
+	bool "Rust reference driver"
+	depends on RUST && AX88796B_PHY
+	default n

Nit, "n" is always the default, there is no need for this line.

Understood, I'll remove this line.

quoted

+	help
+	  Uses the Rust version driver for Asix PHYs.

You need more text here please.  Provide a better description of what
hardware is supported and the name of the module if it is built aas a
module.

Also that if you select this one, the C driver will not be built (which
is not expressed in the Kconfig language, why not?

Because the way to load a PHY driver module can't handle multiple
modules with the same phy id (a NIC driver loads a PHY driver module).
There is no machinism to specify which PHY driver module should be
loaded when multiple PHY modules have the same phy id (as far as I know).

The Kconfig file would be like the following. AX88796B_RUST_PHY
depends on AX88796B_PHY so the description of AX88796B_PHY is enough?
I'll add the name of the module.


config AX88796B_PHY
	tristate "Asix PHYs"
	help
	  Currently supports the Asix Electronics PHY found in the X-Surf 100
	  AX88796B package.

config AX88796B_RUST_PHY
	bool "Rust reference driver"
	depends on RUST && AX88796B_PHY
	default n
	help
	  Uses the Rust version driver for Asix PHYs.

quoted

+
 config BROADCOM_PHY
 	tristate "Broadcom 54XX PHYs"
 	select BCM_NET_PHYLIB

diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index c945ed9bd14b..58d7dfb095ab 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile

@@ -41,7 +41,11 @@ aquantia-objs			+= aquantia_hwmon.o
 endif
 obj-$(CONFIG_AQUANTIA_PHY)	+= aquantia.o
 obj-$(CONFIG_AT803X_PHY)	+= at803x.o
-obj-$(CONFIG_AX88796B_PHY)	+= ax88796b.o
+ifdef CONFIG_AX88796B_RUST_PHY
+  obj-$(CONFIG_AX88796B_PHY)	+= ax88796b_rust.o
+else
+  obj-$(CONFIG_AX88796B_PHY)	+= ax88796b.o
+endif

This can be expressed in Kconfig, no need to put this here, right?

Not sure. Is it possible? If we allow both modules to be built, I
guess it's possible though.

quoted

 obj-$(CONFIG_BCM54140_PHY)	+= bcm54140.o
 obj-$(CONFIG_BCM63XX_PHY)	+= bcm63xx.o
 obj-$(CONFIG_BCM7XXX_PHY)	+= bcm7xxx.o

diff --git a/drivers/net/phy/ax88796b_rust.rs b/drivers/net/phy/ax88796b_rust.rs
new file mode 100644
index 000000000000..d11c82a9e847
--- /dev/null
+++ b/drivers/net/phy/ax88796b_rust.rs

@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0

No copyright line?  Are you sure?

Ah, I'll add.