Re: [PATCH v1 2/4] hwmon: (acpi_power_meter) Fix update the power trip points on failure

["lihuisong (C)" <lihuisong@huawei.com>]

在 2024/11/25 23:22, Guenter Roeck 写道:
> On 11/25/24 01:34, Huisong Li wrote:
>> The power trip points maintained in local should not be updated when 
>> '_PTP'
>> method fails to evaluate.
>>
>> Signed-off-by: Huisong Li <lihuisong@huawei.com>
>> ---
>>   drivers/hwmon/acpi_power_meter.c | 5 ++++-
>>   1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/hwmon/acpi_power_meter.c 
>> b/drivers/hwmon/acpi_power_meter.c
>> index 4c3314e35d30..95da73858a0b 100644
>> --- a/drivers/hwmon/acpi_power_meter.c
>> +++ b/drivers/hwmon/acpi_power_meter.c
>> @@ -292,8 +292,8 @@ static ssize_t set_trip(struct device *dev, 
>> struct device_attribute *devattr,
>>       struct sensor_device_attribute *attr = 
>> to_sensor_dev_attr(devattr);
>>       struct acpi_device *acpi_dev = to_acpi_device(dev);
>>       struct acpi_power_meter_resource *resource = 
>> acpi_dev->driver_data;
>> +    unsigned long temp, trip_bk;
>>       int res;
>> -    unsigned long temp;
>>         res = kstrtoul(buf, 10, &temp);
>>       if (res)
>> @@ -302,8 +302,11 @@ static ssize_t set_trip(struct device *dev, 
>> struct device_attribute *devattr,
>>       temp = DIV_ROUND_CLOSEST(temp, 1000);
>>         mutex_lock(&resource->lock);
>> +    trip_bk = resource->trip[attr->index - 7];
>>       resource->trip[attr->index - 7] = temp;
>>       res = set_acpi_trip(resource);
>> +    if (!res)
>> +        resource->trip[attr->index - 7] = trip_bk;
>
> Unless I am missing something, this restores the old value if setting
> the new value succeeded. Please explain.
>
Yes, you are right.
Restore the old value on faiure. will fix it.
>
>> mutex_unlock(&resource->lock);
>>         if (res)
>
> .