1 files changed, 1 insertions, 0 deletions
diff --git a/os/hal/ports/STM32/LLD/USARTv2/hal_serial_lld.c b/os/hal/ports/STM32/LLD/USARTv2/hal_serial_lld.c
index 6c2b855af..a89c02b24 100644
--- a/os/hal/ports/STM32/LLD/USARTv2/hal_serial_lld.c
+++ b/os/hal/ports/STM32/LLD/USARTv2/hal_serial_lld.c
@@ -366,6 +366,7 @@ static void serve_interrupt(SerialDriver *sdp) {
       if (b < MSG_OK) {
         chnAddFlagsI(sdp, CHN_OUTPUT_EMPTY);
         u->CR1 = cr1 & ~USART_CR1_TXEIE;
+        osalSysUnlockFromISR();
         break;
       }
       u->TDR = b;