[PATCH] firmware: qcom: scm: Hide QCOM_SCM instead of depending on ARCH_QCOM

[Sasha Levin]

imx_v6_v7_defconfig fails to link:

  arm-linux-gnueabihf-ld: drivers/firmware/qcom/qcom_scm.o: in function
  `qcom_scm_pas_init_image':
  qcom_scm.c:(.text+0xecc): undefined reference to `qcom_tzmem_alloc'
  qcom_scm.c:(.text+0x2b0): undefined reference to `qcom_tzmem_free'
  qcom_scm.c:(.text+0x1514): undefined reference to `qcom_tzmem_to_phys'

QCOM_SCM gained a "depends on ARCH_QCOM || COMPILE_TEST", but it is
selected from 20 places in the tree and several of those are reachable
without ARCH_QCOM. DRM_MSM is one of them, via SOC_IMX5, which is how
imx_v6_v7_defconfig ends up here:

  WARNING: unmet direct dependencies detected for QCOM_SCM
    Depends on [n]: ARCH_QCOM [=n] || COMPILE_TEST [=n]
    Selected by [y]:
    - DRM_MSM [=y] && ... && (ARCH_QCOM [=n] || SOC_IMX5 [=y] ||
      COMPILE_TEST [=n]) && ...

kconfig still honours the select and sets QCOM_SCM=y, but it does not
propagate the selects of a symbol whose own dependencies are unmet, so
QCOM_TZMEM is left unset, qcom_tzmem.c is not built, and the
unconditional qcom_tzmem_*() calls in qcom_scm.c and qcom_scm-smc.c
have nothing to bind to.

The point of the dependency was only to stop asking the user about
Qualcomm firmware interfaces when configuring a non-Qualcomm kernel.
Express that as a prompt condition, which is what the same commit
already did for QCOM_PAS: the symbol stays invisible, but it no longer
carries a dependency that silently drops its selects.

Found by KernelCI builds of the linus-next tree.

Fixes: 8fecd3194de3 ("firmware: QCOM interfaces should depend on ARCH_QCOM")
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202609120634.g0HMAp3g-lkp@xxxxxxxxx/
Assisted-by: LLM
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/firmware/qcom/Kconfig | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/firmware/qcom/Kconfig b/drivers/firmware/qcom/Kconfig
index 691db0ded8e8c..b50e1309ced5f 100644
--- a/drivers/firmware/qcom/Kconfig
+++ b/drivers/firmware/qcom/Kconfig
@@ -26,8 +26,7 @@ config QCOM_PAS_TEE
 	  by the firmware TEE implementation as the backend.
 
 config QCOM_SCM
-	tristate "Qualcomm PAS SCM interface driver"
-	depends on ARCH_QCOM || COMPILE_TEST
+	tristate "Qualcomm PAS SCM interface driver" if ARCH_QCOM || COMPILE_TEST
 	select QCOM_PAS
 	select QCOM_TZMEM
 	default y if ARCH_QCOM
-- 
2.53.0