Re: [PATCH 3/7] power: supply: core: fix HWMON temperature labels

[Guenter Roeck]

On 4/2/20 8:00 AM, Michał Mirosław wrote:
> On Thu, Apr 02, 2020 at 07:52:19AM -0700, Guenter Roeck wrote:
>> On 4/2/20 7:46 AM, Michał Mirosław wrote:
>>> tempX_label files are swapped compared to what
>>> power_supply_hwmon_temp_to_property() uses. Make them match.
>>> While at it, make room for labeling other channels.
>>>
>>> Fixes: e67d4dfc9ff1 ("power: supply: Add HWMON compatibility layer")
>>> Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx>
>>> ---
>>>  drivers/power/supply/power_supply_hwmon.c | 14 +++++++++++++-
>>>  1 file changed, 13 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/power/supply/power_supply_hwmon.c b/drivers/power/supply/power_supply_hwmon.c
>>> index 75cf861ba492..83318a21fb52 100644
>>> --- a/drivers/power/supply/power_supply_hwmon.c
>>> +++ b/drivers/power/supply/power_supply_hwmon.c
>>> @@ -43,6 +43,11 @@ static int power_supply_hwmon_curr_to_property(u32 attr)
>>>  	}
>>>  }
>>>  
>>> +static const char *const ps_temp_label[] = {
>>> +	"temp",
>>> +	"ambient temp",
>>> +};
>>> +
>>>  static int power_supply_hwmon_temp_to_property(u32 attr, int channel)
>>>  {
>>>  	if (channel) {
>>> @@ -144,7 +149,14 @@ static int power_supply_hwmon_read_string(struct device *dev,
>>>  					  u32 attr, int channel,
>>>  					  const char **str)
>>>  {
>>> -	*str = channel ? "temp" : "temp ambient";
>>> +	switch (type) {
>>> +	case hwmon_temp:
>>> +		*str = ps_temp_label[channel];
>>> +		break;
>>> +	default:
>>> +		break;
>>
>> That returns "no error" without setting *str, which is really asking for trouble.
> 
> This is carried over from earlier version. No bug though, but I'll add a
> patch while I'm at it.
> 

This is incorrect. The previous version does not check the type and always sets *str.

-	*str = channel ? "temp" : "temp ambient";

Guenter