On Tue, Mar 15, 2022 at 3:41 PM Randy Dunlap <rdunlap@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx>
> From: Igor Zhbanov <i.zhbanov@xxxxxxxxxxxx>
What does this From tag mean?
> Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@xxxxxxxxxxxx
> Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Cc: John Stultz <john.stultz@xxxxxxxxxx>
> Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
> Cc: linux-acpi@xxxxxxxxxxxxxxx
> ---
> v3: also cc: linux-acpi (Rafael)
> v2: correct the Fixes: tag (Dan Carpenter)
>
> drivers/clocksource/acpi_pm.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> --- linux-next-20220315.orig/drivers/clocksource/acpi_pm.c
> +++ linux-next-20220315/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);
