Re: [PATCH 2/2] [v2] qcom_scm: hide Kconfig symbol

[Alex Elder]

On 9/28/21 2:50 AM, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> Now that SCM can be a loadable module, we have to add another
> dependency to avoid link failures when ipa or adreno-gpu are
> built-in:
>
> aarch64-linux-ld: drivers/net/ipa/ipa_main.o: in function `ipa_probe':
> ipa_main.c:(.text+0xfc4): undefined reference to `qcom_scm_is_available'
>
> ld.lld: error: undefined symbol: qcom_scm_is_available
> > > > referenced by adreno_gpu.c
> > > >                gpu/drm/msm/adreno/adreno_gpu.o:(adreno_zap_shader_load) in archive drivers/built-in.a
>
> This can happen when CONFIG_ARCH_QCOM is disabled and we don't select
> QCOM_MDT_LOADER, but some other module selects QCOM_SCM. Ideally we'd
> use a similar dependency here to what we have for QCOM_RPROC_COMMON,
> but that causes dependency loops from other things selecting QCOM_SCM.
>
> This appears to be an endless problem, so try something different this
> time:
>
>   - CONFIG_QCOM_SCM becomes a hidden symbol that nothing 'depends on'
>     but that is simply selected by all of its users
>
>   - All the stubs in include/linux/qcom_scm.h can go away
>
>   - arm-smccc.h needs to provide a stub for __arm_smccc_smc() to
>     allow compile-testing QCOM_SCM on all architectures.
>
>   - To avoid a circular dependency chain involving RESET_CONTROLLER
>     and PINCTRL_SUNXI, drop the 'select RESET_CONTROLLER' statement.
>     According to my testing this still builds fine, and the QCOM
>     platform selects this symbol already.
>
> Acked-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> Changes in v2:
>    - drop the 'select RESET_CONTROLLER' line, rather than adding
>      more of the same
> ---
>   drivers/firmware/Kconfig                |  5 +-
>   drivers/gpu/drm/msm/Kconfig             |  4 +-
>   drivers/iommu/Kconfig                   |  2 +-
>   drivers/media/platform/Kconfig          |  2 +-
>   drivers/mmc/host/Kconfig                |  2 +-
>   drivers/net/ipa/Kconfig                 |  1 +

For drivers/net/ipa/Kconfig, looks good to me.
Nice simplification.

Acked-by: Alex Elder <elder@xxxxxxxxxx>

>   drivers/net/wireless/ath/ath10k/Kconfig |  2 +-
>   drivers/pinctrl/qcom/Kconfig            |  3 +-
>   include/linux/arm-smccc.h               | 10 ++++
>   include/linux/qcom_scm.h                | 71 -------------------------
>   10 files changed, 20 insertions(+), 82 deletions(-)

. . .