[Bug target/64953] Compiling sourcecode for STM32F103 causes USB errors with some optimization settings

[manuel.reimer at gmx dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64953

--- Comment #3 from manuel.reimer at gmx dot de ---
Thank you for your suggestion. This helped me to narrow this down to the
function "usbReset":

https://github.com/tormodvolden/maple-bootloader/blob/unify_platforms/usb.c#L258

If I use "-Os" on everything but this one function, then the result still
produces one error if I plug in, but stabilizes shortly after that and then
works well.