Re: [PATCH] PCI: cadence: Kconfig: change PCIE_CADENCE configs from tristate to bool

["Arnd Bergmann" <arnd@arndb.de>]

On Thu, Nov 13, 2025, at 10:27, Siddharth Vadapalli wrote:
> The drivers associated with the PCIE_CADENCE, PCIE_CADENCE_HOST AND
> PCIE_CADENCE_EP configs are used by multiple vendor drivers and serve as a
> library of helpers. Since the vendor drivers could individually be built
> as built-in or as loadable modules, it is possible to select a build
> configuration wherein a vendor driver is built-in while the library is
> built as a loadable module. This will result in a build error as reported
> in the 'Closes' link below.
>
> Address the build error by changing the library configs to be 'bool'
> instead of 'tristate'.
>
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: 
> https://lore.kernel.org/oe-kbuild-all/202511111705.MZ7ls8Hm-lkp@intel.com/
> Fixes: 1c72774df028 ("PCI: sg2042: Add Sophgo SG2042 PCIe driver")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>

I really think there has to be a better solution here, this is not
an unusual problem.

> @@ -4,16 +4,16 @@ menu "Cadence-based PCIe controllers"
>  	depends on PCI
> 
>  config PCIE_CADENCE
> -	tristate
> +	bool
> 
>  config PCIE_CADENCE_HOST
> -	tristate
> +	bool
>  	depends on OF
>  	select IRQ_DOMAIN
>  	select PCIE_CADENCE
> 
>  config PCIE_CADENCE_EP
> -	tristate
> +	bool
>  	depends on OF
>  	depends on PCI_ENDPOINT
>  	select PCIE_CADENCE

I think the easiest way would be to leave PCIE_CADENCE as
a 'tristate' symbol but make the other two 'bool', and then
adjust the Makefile logic to use CONFIG_PCIE_CADENCE as
the thing that controls how the individual drivers are built.

That way, if any platform specific driver is built-in, both
the EP and HOST support are built-in or disabled but never
loadable modules. As long as all platform drivers are
loadable modules, so would be the base support.

     Arnd