tone init is very long when used with NULL value.

Hi,

In some Arduino sketches, we can find the usage of tone in this way : 
     tone (Pin, 0);

In the Arduino_Core_STM32, this is taking long time. When doing this, we spend a lot of time in TimerPinInit function. We search for a prescaler value and never found it.

(I agree that it would be better to use noTone function in this case...)

Regards
 