linux/drivers/net/dsa/realtek/Kconfig

53 lines
1.4 KiB
Text
Raw Permalink Normal View History

# SPDX-License-Identifier: GPL-2.0-only
menuconfig NET_DSA_REALTEK
tristate "Realtek Ethernet switch family support"
depends on NET_DSA
select FIXED_PHY
select IRQ_DOMAIN
select REALTEK_PHY
select REGMAP
help
Select to enable support for Realtek Ethernet switch chips.
net: dsa: realtek: fix Kconfig to assure consistent driver linkage The kernel test robot reported a build failure: or1k-linux-ld: drivers/net/dsa/realtek/realtek-smi.o:(.rodata+0x16c): undefined reference to `rtl8366rb_variant' ... with the following build configuration: CONFIG_NET_DSA_REALTEK=y CONFIG_NET_DSA_REALTEK_SMI=y CONFIG_NET_DSA_REALTEK_RTL8365MB=y CONFIG_NET_DSA_REALTEK_RTL8366RB=m The problem here is that the realtek-smi interface driver gets built-in, while the rtl8366rb switch subdriver gets built as a module, hence the symbol rtl8366rb_variant is not reachable when defining the OF device table in the interface driver. The Kconfig dependencies don't help in this scenario because they just say that the subdriver(s) depend on at least one interface driver. In fact, the subdrivers don't depend on the interface drivers at all, and can even be built even in their absence. Somewhat strangely, the interface drivers can also be built in the absence of any subdriver, BUT, if a subdriver IS enabled, then it must be reachable according to the linkage of the interface driver: effectively what the IS_REACHABLE() macro achieves. If it is not reachable, the above kind of linker error will be observed. Rather than papering over the above build error by simply using IS_REACHABLE(), we can do a little better and admit that it is actually the interface drivers that have a dependency on the subdrivers. So this patch does exactly that. Specifically, we ensure that: 1. The interface drivers' Kconfig symbols must have a value no greater than the value of any subdriver Kconfig symbols. 2. The subdrivers should by default enable both interface drivers, since most users probably want at least one of them; those interface drivers can be explicitly disabled however. What this doesn't do is prevent a user from building only a subdriver, without any interface driver. To that end, add an additional line of help in the menu to guide users in the right direction. Link: https://lore.kernel.org/all/202204110757.XIafvVnj-lkp@intel.com/ Reported-by: kernel test robot <lkp@intel.com> Fixes: aac94001067d ("net: dsa: realtek: add new mdio interface for drivers") Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-12 17:55:27 +02:00
Note that at least one interface driver must be enabled for the
subdrivers to be loaded. Moreover, an interface driver cannot achieve
anything without at least one subdriver enabled.
if NET_DSA_REALTEK
config NET_DSA_REALTEK_MDIO
bool "Realtek MDIO interface support"
depends on OF
help
Select to enable support for registering switches configured
through MDIO.
config NET_DSA_REALTEK_SMI
bool "Realtek SMI interface support"
depends on OF
help
Select to enable support for registering switches connected
through SMI.
config NET_DSA_REALTEK_RTL8365MB
tristate "Realtek RTL8365MB switch driver"
depends on NET_DSA_REALTEK_SMI || NET_DSA_REALTEK_MDIO
select NET_DSA_TAG_RTL8_4
help
Select to enable support for Realtek RTL8365MB-VC and RTL8367S.
config NET_DSA_REALTEK_RTL8366RB
tristate "Realtek RTL8366RB switch driver"
depends on NET_DSA_REALTEK_SMI || NET_DSA_REALTEK_MDIO
select NET_DSA_TAG_RTL4_A
help
net: dsa: realtek: fix Kconfig to assure consistent driver linkage The kernel test robot reported a build failure: or1k-linux-ld: drivers/net/dsa/realtek/realtek-smi.o:(.rodata+0x16c): undefined reference to `rtl8366rb_variant' ... with the following build configuration: CONFIG_NET_DSA_REALTEK=y CONFIG_NET_DSA_REALTEK_SMI=y CONFIG_NET_DSA_REALTEK_RTL8365MB=y CONFIG_NET_DSA_REALTEK_RTL8366RB=m The problem here is that the realtek-smi interface driver gets built-in, while the rtl8366rb switch subdriver gets built as a module, hence the symbol rtl8366rb_variant is not reachable when defining the OF device table in the interface driver. The Kconfig dependencies don't help in this scenario because they just say that the subdriver(s) depend on at least one interface driver. In fact, the subdrivers don't depend on the interface drivers at all, and can even be built even in their absence. Somewhat strangely, the interface drivers can also be built in the absence of any subdriver, BUT, if a subdriver IS enabled, then it must be reachable according to the linkage of the interface driver: effectively what the IS_REACHABLE() macro achieves. If it is not reachable, the above kind of linker error will be observed. Rather than papering over the above build error by simply using IS_REACHABLE(), we can do a little better and admit that it is actually the interface drivers that have a dependency on the subdrivers. So this patch does exactly that. Specifically, we ensure that: 1. The interface drivers' Kconfig symbols must have a value no greater than the value of any subdriver Kconfig symbols. 2. The subdrivers should by default enable both interface drivers, since most users probably want at least one of them; those interface drivers can be explicitly disabled however. What this doesn't do is prevent a user from building only a subdriver, without any interface driver. To that end, add an additional line of help in the menu to guide users in the right direction. Link: https://lore.kernel.org/all/202204110757.XIafvVnj-lkp@intel.com/ Reported-by: kernel test robot <lkp@intel.com> Fixes: aac94001067d ("net: dsa: realtek: add new mdio interface for drivers") Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-12 17:55:27 +02:00
Select to enable support for Realtek RTL8366RB.
config NET_DSA_REALTEK_RTL8366RB_LEDS
bool
depends on (LEDS_CLASS=y || LEDS_CLASS=NET_DSA_REALTEK_RTL8366RB)
depends on NET_DSA_REALTEK_RTL8366RB
default NET_DSA_REALTEK_RTL8366RB
net: dsa: realtek: fix Kconfig to assure consistent driver linkage The kernel test robot reported a build failure: or1k-linux-ld: drivers/net/dsa/realtek/realtek-smi.o:(.rodata+0x16c): undefined reference to `rtl8366rb_variant' ... with the following build configuration: CONFIG_NET_DSA_REALTEK=y CONFIG_NET_DSA_REALTEK_SMI=y CONFIG_NET_DSA_REALTEK_RTL8365MB=y CONFIG_NET_DSA_REALTEK_RTL8366RB=m The problem here is that the realtek-smi interface driver gets built-in, while the rtl8366rb switch subdriver gets built as a module, hence the symbol rtl8366rb_variant is not reachable when defining the OF device table in the interface driver. The Kconfig dependencies don't help in this scenario because they just say that the subdriver(s) depend on at least one interface driver. In fact, the subdrivers don't depend on the interface drivers at all, and can even be built even in their absence. Somewhat strangely, the interface drivers can also be built in the absence of any subdriver, BUT, if a subdriver IS enabled, then it must be reachable according to the linkage of the interface driver: effectively what the IS_REACHABLE() macro achieves. If it is not reachable, the above kind of linker error will be observed. Rather than papering over the above build error by simply using IS_REACHABLE(), we can do a little better and admit that it is actually the interface drivers that have a dependency on the subdrivers. So this patch does exactly that. Specifically, we ensure that: 1. The interface drivers' Kconfig symbols must have a value no greater than the value of any subdriver Kconfig symbols. 2. The subdrivers should by default enable both interface drivers, since most users probably want at least one of them; those interface drivers can be explicitly disabled however. What this doesn't do is prevent a user from building only a subdriver, without any interface driver. To that end, add an additional line of help in the menu to guide users in the right direction. Link: https://lore.kernel.org/all/202204110757.XIafvVnj-lkp@intel.com/ Reported-by: kernel test robot <lkp@intel.com> Fixes: aac94001067d ("net: dsa: realtek: add new mdio interface for drivers") Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-12 17:55:27 +02:00
endif