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The classic-USB STM32 fsdev driver enabled the EXTI-line USB wakeup interrupt (USBWakeUp_IRQn, and USBWakeUp_RMP_IRQn on the F3 remap path) in the NVIC, but never uses it: resume is serviced in-band via ISTR.WKUP in the USB_LP/HP ISR, and the driver never arms or clears that EXTI line. The wakeup EXTI interrupt is only needed to wake the core from STOP mode, which TinyUSB does not implement. Leaving its NVIC vector enabled lets it fire spuriously into an unhandled or looping vector -- the freeze reported in #3696 on STM32G473. USBWakeUp_IRQn is a valid, dedicated USB-wakeup-via-EXTI interrupt (e.g. stm32g473xx.h: =42 "USB Wakeup through EXTI line"), not an "unrelated interrupt"; it is simply unused here. - Comment out USBWakeUp_IRQn for F1/F3/G4/L1 and USBWakeUp_RMP_IRQn on the F3 remap path, kept in place so STOP-mode wakeup is a one-line re-enable. - Keep the STM32L1 USBWakeUp_IRQn -> USB_FS_WKUP_IRQn alias for that re-enable. - Document the rationale in fsdev_stm32.h with a TODO. - Comment out the matching USBWakeUp(_RMP)_IRQHandler in the F1/F3/G4 BSPs, and the FreeRTOS NVIC_SetPriority(USBWakeUp_IRQn) on F1/G4. Fixes #3696 Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>