diff --git a/components/soc/esp32/include/hal/uart_ll.h b/components/soc/esp32/include/hal/uart_ll.h index 1b70503527..33002ca47a 100644 --- a/components/soc/esp32/include/hal/uart_ll.h +++ b/components/soc/esp32/include/hal/uart_ll.h @@ -167,6 +167,9 @@ FORCE_INLINE_ATTR void uart_ll_read_rxfifo(uart_dev_t *hw, uint8_t *buf, uint32_ uint32_t fifo_addr = (hw == &UART0) ? UART_FIFO_REG(0) : (hw == &UART1) ? UART_FIFO_REG(1) : UART_FIFO_REG(2); for(uint32_t i = 0; i < rd_len; i++) { buf[i] = READ_PERI_REG(fifo_addr); +#ifdef CONFIG_COMPILER_OPTIMIZATION_PERF + __asm__ __volatile__("nop"); +#endif } }