[PATCH v2 RESEND] ARM: fix unmet dependency on BITREVERSE for HAVE_ARCH_BITREVERSE

Julian Braha julianbraha at gmail.com
Sun Jan 16 20:09:40 PST 2022


Resending this to properly add it to the patch tracker - thanks for letting
me know, Arnd :)

When ARM is enabled, and BITREVERSE is disabled,
Kbuild gives the following warning:

WARNING: unmet direct dependencies detected for HAVE_ARCH_BITREVERSE
  Depends on [n]: BITREVERSE [=n]
  Selected by [y]:
  - ARM [=y] && (CPU_32v7M [=n] || CPU_32v7 [=y]) && !CPU_32v6 [=n]

This is because ARM selects HAVE_ARCH_BITREVERSE
without selecting BITREVERSE, despite
HAVE_ARCH_BITREVERSE depending on BITREVERSE.

This unmet dependency bug was found by Kismet,
a static analysis tool for Kconfig. Please advise if this
is not the appropriate solution.

Signed-off-by: Julian Braha <julianbraha at gmail.com>
---
v2:
Changed this fix to remove the dependency on BITREVERSE from
HAVE_ARCH_BITREVERSE, since it isn't actually necessary.

v1 link:
https://lore.kernel.org/linux-arm-kernel/20211029203110.8343-1-julianbraha@gmail.com/

KernelVersion: v5.16-rc5

 lib/Kconfig | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lib/Kconfig b/lib/Kconfig
index c80fde816a7e..9b5a692ce00c 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -45,7 +45,6 @@ config BITREVERSE
 config HAVE_ARCH_BITREVERSE
 	bool
 	default n
-	depends on BITREVERSE
 	help
 	  This option enables the use of hardware bit-reversal instructions on
 	  architectures which support such operations.
--
2.32.0



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