[PATCH net v3] net/iucv: require IUCV for AF_IUCV sockets

AFIUCV can currently be selected with IUCV disabled. That configuration
does not build af_iucv.o because the parent Makefile only enters
net/iucv under CONFIG_IUCV. Independently entering the directory is not
sufficient: AF_IUCV also relies on the IUCV implementation.

Restore the IUCV dependency for AFIUCV, as proposed during review. This
also constrains AFIUCV to a module when its IUCV provider is modular,
without changing the directory traversal rules.

The issue was found by our static-analysis tool.

Fixes: c69748d1c9b5 ("iucv: kernel option for z/VM IUCV and HiperSockets")
Assisted-by: gpt 5
Signed-off-by: Pengpeng Hou <redacted>
---
Changes since v2:
https://lore.kernel.org/all/20260815135456.53684-1-pengpeng@iscas.ac.cn/ (local)
Replace the v2 always-descend approach with the IUCV dependency proposed
by Alexandra. Do not carry the review tag for the superseded
implementation.

 net/iucv/Kconfig |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/iucv/Kconfig b/net/iucv/Kconfig
index 5cfddc9c6498..2686d795cc2f 100644
--- a/net/iucv/Kconfig
+++ b/net/iucv/Kconfig

@@ -9,7 +9,7 @@ config IUCV
 	  communication link between VM guests.
 
 config AFIUCV
-	depends on S390
+	depends on IUCV
 	def_tristate m if QETH_L3 || IUCV
 	prompt "AF_IUCV Socket support (S390 - z/VM and HiperSockets transport)"
 	help

base-commit: 518e5b794c06c0f0eb40df3e202274a66202c137
-- 
2.50.1 (Apple Git-155)