Re: [PATCH] mfd: wm8350: propagate ADC read timeout instead of returning 0

[Guenter Roeck]

On 8/4/26 18:42, Ivy Lopez wrote:
> wm8350_read_auxadc() logs an error via dev_err() when the AUX ADC
> read times out, but then falls through to return the masked value
> of `result`, which was left at its initial value of 0. Callers have
> no way to distinguish a genuine 0V reading from a failed read.
>
> Return -ETIMEDOUT on timeout instead, and update the wm8350 hwmon
> and power_supply drivers, which call this function directly, to
> check for a negative return and propagate the error rather than
> using it as a voltage value.

I am not sure if this warrants fixing in a 17+ year old driver,
unless it is observed to be a real problem. It appears to me that the
error handling was likely not implemented on purpose.

On top of that, as is seen a lot lately, this fixes a rare issue
that is likely never going to be seen in the real world while not
addressing the many real problems in the driver (as reported by Sashiko).

Guenter