From: Arnd Bergmann <arnd@arndb.de>

Compile-testing this driver is only possible when the AMBA bus driver is
available in the kernel:

x86_64-linux-ld: drivers/char/hw_random/nomadik-rng.o: in function `nmk_rng_remove':
nomadik-rng.c:(.text+0x67): undefined reference to `amba_release_regions'
x86_64-linux-ld: drivers/char/hw_random/nomadik-rng.o: in function `nmk_rng_probe':
nomadik-rng.c:(.text+0xee): undefined reference to `amba_request_regions'
x86_64-linux-ld: nomadik-rng.c:(.text+0x18d): undefined reference to `amba_release_regions'

The was previously implied by the 'depends on ARCH_NOMADIK', but needs to be
specified for the COMPILE_TEST case.

Fixes: d5e93b3374e4 ("hwrng: Kconfig - Add helper dependency on COMPILE_TEST")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/char/hw_random/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 3227dcaa9111..aef4406973f3 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -312,6 +312,7 @@ config HW_RANDOM_INGENIC_TRNG
 config HW_RANDOM_NOMADIK
 	tristate "ST-Ericsson Nomadik Random Number Generator support"
 	depends on ARCH_NOMADIK || COMPILE_TEST
+	depends on ARM_AMBA
 	default HW_RANDOM
 	help
 	  This driver provides kernel-side support for the Random Number
-- 
2.39.5

Hi Arnd,

On Tue, 29 Jul 2025 at 17:28, Arnd Bergmann <arnd@kernel.org> wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> Compile-testing this driver is only possible when the AMBA bus driver is
> available in the kernel:
>
> x86_64-linux-ld: drivers/char/hw_random/nomadik-rng.o: in function `nmk_rng_remove':
> nomadik-rng.c:(.text+0x67): undefined reference to `amba_release_regions'
> x86_64-linux-ld: drivers/char/hw_random/nomadik-rng.o: in function `nmk_rng_probe':
> nomadik-rng.c:(.text+0xee): undefined reference to `amba_request_regions'
> x86_64-linux-ld: nomadik-rng.c:(.text+0x18d): undefined reference to `amba_release_regions'
>
> The was previously implied by the 'depends on ARCH_NOMADIK', but needs to be
> specified for the COMPILE_TEST case.
>
> Fixes: d5e93b3374e4 ("hwrng: Kconfig - Add helper dependency on COMPILE_TEST")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks for your patch, which is now commit efaa2d815a0e4d1c ("hwrng:
nomadik - add ARM_AMBA dependency") upstream.

> --- a/drivers/char/hw_random/Kconfig
> +++ b/drivers/char/hw_random/Kconfig
> @@ -312,6 +312,7 @@ config HW_RANDOM_INGENIC_TRNG
>  config HW_RANDOM_NOMADIK
>         tristate "ST-Ericsson Nomadik Random Number Generator support"
>         depends on ARCH_NOMADIK || COMPILE_TEST
> +       depends on ARM_AMBA
>         default HW_RANDOM
>         help
>           This driver provides kernel-side support for the Random Number

After seeing CONFIG_HW_RANDOM_NOMADIK disappear from m68k
all{mod,yes}config, I became intrigued, as it did build fine before?
If CONFIG_ARM_AMBA is not enabled, both __amba_driver_register() and
amba_driver_unregister() become static inline dummies, and the rest
of the code and data is not referenced, thus optimized away by the
compiler.  I verified this is the case on amd64 allmodconfig, too.
How come this failed for you?

Gr{oetje,eeting}s,

                        Geert


--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

On Tue, Jul 29, 2025 at 05:28:00PM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> Compile-testing this driver is only possible when the AMBA bus driver is
> available in the kernel:
> 
> x86_64-linux-ld: drivers/char/hw_random/nomadik-rng.o: in function `nmk_rng_remove':
> nomadik-rng.c:(.text+0x67): undefined reference to `amba_release_regions'
> x86_64-linux-ld: drivers/char/hw_random/nomadik-rng.o: in function `nmk_rng_probe':
> nomadik-rng.c:(.text+0xee): undefined reference to `amba_request_regions'
> x86_64-linux-ld: nomadik-rng.c:(.text+0x18d): undefined reference to `amba_release_regions'
> 
> The was previously implied by the 'depends on ARCH_NOMADIK', but needs to be
> specified for the COMPILE_TEST case.
> 
> Fixes: d5e93b3374e4 ("hwrng: Kconfig - Add helper dependency on COMPILE_TEST")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/char/hw_random/Kconfig | 1 +
>  1 file changed, 1 insertion(+)

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt