__setup() handlers should return 1 to obsolete_checksetup() in
init/main.c to indicate that the boot option has been handled.
A return of 0 causes the boot option/value to be listed as an Unknown
kernel parameter and added to init's (limited) argument or environment
strings. Also, error return codes don't mean anything to
obsolete_checksetup() -- only non-zero (usually 1) or zero.
So return 1 from setup_nmi_watchdog().

Fixes: e5553a6d0442 ("sparc64: Implement NMI watchdog on capable cpus.")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <izh1979@gmail.com>
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andreas Larsson <andreas@gaisler.com>
---
v2: change From: Igor to Reported-by:
    add more Cc's
v3: use Igor's current email address
v4: add Arnd to Cc: list
v5: add Andreas to Cc: list

 arch/sparc/kernel/nmi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -- a/arch/sparc/kernel/nmi.c b/arch/sparc/kernel/nmi.c
--- a/arch/sparc/kernel/nmi.c
+++ b/arch/sparc/kernel/nmi.c
@@ -279,7 +279,7 @@ static int __init setup_nmi_watchdog(cha
 	if (!strncmp(str, "panic", 5))
 		panic_on_timeout = 1;
 
-	return 0;
+	return 1;
 }
 __setup("nmi_watchdog=", setup_nmi_watchdog);

On 2024-02-11 06:28, Randy Dunlap wrote:
> __setup() handlers should return 1 to obsolete_checksetup() in
> init/main.c to indicate that the boot option has been handled.
> A return of 0 causes the boot option/value to be listed as an Unknown
> kernel parameter and added to init's (limited) argument or environment
> strings. Also, error return codes don't mean anything to
> obsolete_checksetup() -- only non-zero (usually 1) or zero.
> So return 1 from setup_nmi_watchdog().
> 
> Fixes: e5553a6d0442 ("sparc64: Implement NMI watchdog on capable cpus.")
> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> Reported-by: Igor Zhbanov <izh1979@gmail.com>
> Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: sparclinux@vger.kernel.org
> Cc: Sam Ravnborg <sam@ravnborg.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: stable@vger.kernel.org
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Andreas Larsson <andreas@gaisler.com>

Applied to my for-next branch.

Thanks,
Andreas