Re: [PATCH] iio: dac: Fix passing uninitialized vref1_uV for no Vref1 case

[David Lechner <dlechner@baylibre.com>]

On 4/14/26 7:48 AM, Andy Shevchenko wrote:
> On Tue, Apr 14, 2026 at 03:33:38PM +0300, Ariana Lazar wrote:
>> Initialize vref1_uV variable to 0 before calling
>> mcp47feb02_init_ch_scales() in mcp47feb02_probe() to avoid passing an
>> uninitialized value when have_ext_vref1 is false.
> 
> ...
> 
>> +	vref1_uV = 0;
>>  	if (chip_features->have_ext_vref1) {
> 
> I'm wondering what will happen if we do the below unconditionally?
> 
>>  		ret = devm_regulator_get_enable_read_voltage(dev, "vref1");
> 
> If we have no regulator, we get a dummy one, right? What is the voltage will
> be? 0?

It will fail with -EINVAL because dummy regulator doesn't have a
voltage specified anywhere.

> 
>>  		if (ret > 0) {
>>  			vref1_uV = ret;
>>  			data->use_vref1 = true;
>>  		} else {
>> -			vref1_uV = 0;
>>  			dev_dbg(dev, "using internal band gap as voltage reference 1.\n");
>>  			dev_dbg(dev, "Vref1 is unavailable.\n");
>>  		}
>