Re: [PATCH] hwmon: (acpi_power_meter) Fix a check for the return value of read_domain_devices().

From: Guenter Roeck
Date: Wed Jan 15 2025 - 09:20:16 EST


On Wed, Jan 15, 2025 at 07:35:32AM +0000, Kazuhiro Abe wrote:
> After commit fabb1f813ec0 ("hwmon: (acpi_power_meter) Fix fail to load
> module on platform without _PMD method"),
> the acpi_power_meter driver fails to load if the platform has _PMD method.
>
> To address this, add a check for successful read_domain_devices().
> Tested on Nvidia Grace machine.
>
> Fixes: fabb1f813ec0 ("hwmon: (acpi_power_meter) Fix fail to load module on platform without _PMD method")
> Signed-off-by: Kazuhiro Abe <fj1078ii@xxxxxxxxxxxxxxxxx>

Checkpatch says:

CHECK: Unnecessary parentheses around 'res != 0'
#108: FILE: drivers/hwmon/acpi_power_meter.c:685:
+ if ((res != 0) && (res != -ENODEV))

No need to resend, I'll fix that up while applying, but please keep it in mind
for the future.

Guenter

> ---
> drivers/hwmon/acpi_power_meter.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c
> index 2f1c9d97ad21..dbf2c606fe15 100644
> --- a/drivers/hwmon/acpi_power_meter.c
> +++ b/drivers/hwmon/acpi_power_meter.c
> @@ -682,7 +682,7 @@ static int setup_attrs(struct acpi_power_meter_resource *resource)
>
> /* _PMD method is optional. */
> res = read_domain_devices(resource);
> - if (res != -ENODEV)
> + if ((res != 0) && (res != -ENODEV))
> return res;
>
> if (resource->caps.flags & POWER_METER_CAN_MEASURE) {