[PATCH] hwmon: (acpi_power_meter) Fix the fake power alarm reporting

From: Huisong Li
Date: Wed Feb 19 2025 - 22:21:14 EST


We encountered a problem that a fake power alarm is reported to
user on the platform unsupported notifications at the second step
below:
1> Query 'power1_alarm' attribute when the power capping occurs.
2> Query 'power1_alarm' attribute when the power capping is over
and the current average power is less then power cap value.

The root cause is that the resource->power_alarm is set to true
at the first step. And power meter use this old value to show
the power alarm state instead of the current the comparison value.

Signed-off-by: Huisong Li <lihuisong@xxxxxxxxxx>
---
drivers/hwmon/acpi_power_meter.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c
index 44afb07409a4..f05986e4f379 100644
--- a/drivers/hwmon/acpi_power_meter.c
+++ b/drivers/hwmon/acpi_power_meter.c
@@ -437,9 +437,13 @@ static ssize_t show_val(struct device *dev,
ret = update_cap(resource);
if (ret)
return ret;
+ resource->power_alarm = resource->power > resource->cap;
+ val = resource->power_alarm;
+ } else {
+ val = resource->power_alarm ||
+ resource->power > resource->cap;
+ resource->power_alarm = resource->power > resource->cap;
}
- val = resource->power_alarm || resource->power > resource->cap;
- resource->power_alarm = resource->power > resource->cap;
break;
case 7:
case 8:
--
2.22.0