[PATCH v2] clocksource: acpi_pm: fix return value of __setup handler

[PATCH v2] clocksource: acpi_pm: fix return value of __setup handler

[Randy Dunlap]

__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) environment strings.

The __setup() handler interface isn't meant to handle negative return
values -- they are non-zero, so they mean "handled" (like a return
value of 1 does), but that's just a quirk. So return 1 from
parse_pmtmr(). Also print a warning message if kstrtouint() returns
an error.

Fixes: 6b148507d3d0 ("pmtmr: allow command line override of ioport")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
From: Igor Zhbanov <i.zhbanov@omprussia.ru>
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
---
v2: correct the Fixes: tag (Dan Carpenter)

 drivers/clocksource/acpi_pm.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- linux-next-20220310.orig/drivers/clocksource/acpi_pm.c
+++ linux-next-20220310/drivers/clocksource/acpi_pm.c
@@ -229,8 +229,10 @@ static int __init parse_pmtmr(char *arg)
 	int ret;
 
 	ret = kstrtouint(arg, 16, &base);
-	if (ret)
-		return ret;
+	if (ret) {
+		pr_warn("PMTMR: invalid 'pmtmr=' value: '%s'\n", arg);
+		return 1;
+	}
 
 	pr_info("PMTMR IOPort override: 0x%04x -> 0x%04x\n", pmtmr_ioport,
 		base);

Re: [PATCH v2] clocksource: acpi_pm: fix return value of __setup handler

[Rafael J. Wysocki]

On Sat, Mar 12, 2022 at 8:52 PM Randy Dunlap <rdunlap@infradead.org> 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) environment strings.
>
> The __setup() handler interface isn't meant to handle negative return
> values -- they are non-zero, so they mean "handled" (like a return
> value of 1 does), but that's just a quirk. So return 1 from
> parse_pmtmr(). Also print a warning message if kstrtouint() returns
> an error.
>
> Fixes: 6b148507d3d0 ("pmtmr: allow command line override of ioport")
> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> From: Igor Zhbanov <i.zhbanov@omprussia.ru>
> Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
> Cc: Dan Carpenter <dan.carpenter@oracle.com>
> Cc: John Stultz <john.stultz@linaro.org>
> Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>

Can you please resend this with a CC to linux-acpi?

> ---
> v2: correct the Fixes: tag (Dan Carpenter)
>
>  drivers/clocksource/acpi_pm.c |    6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> --- linux-next-20220310.orig/drivers/clocksource/acpi_pm.c
> +++ linux-next-20220310/drivers/clocksource/acpi_pm.c
> @@ -229,8 +229,10 @@ static int __init parse_pmtmr(char *arg)
>         int ret;
>
>         ret = kstrtouint(arg, 16, &base);
> -       if (ret)
> -               return ret;
> +       if (ret) {
> +               pr_warn("PMTMR: invalid 'pmtmr=' value: '%s'\n", arg);
> +               return 1;
> +       }
>
>         pr_info("PMTMR IOPort override: 0x%04x -> 0x%04x\n", pmtmr_ioport,
>                 base);