diff --git a/libcpu/avr32/uc3/context_gcc.S b/libcpu/avr32/uc3/context_gcc.x
similarity index 100%
rename from libcpu/avr32/uc3/context_gcc.S
rename to libcpu/avr32/uc3/context_gcc.x
diff --git a/libcpu/avr32/uc3/exception.S b/libcpu/avr32/uc3/exception.x
similarity index 100%
rename from libcpu/avr32/uc3/exception.S
rename to libcpu/avr32/uc3/exception.x
diff --git a/libcpu/avr32/uc3/serial.c b/libcpu/avr32/uc3/serial.c
index 3cefbd5843..15431e20f4 100644
--- a/libcpu/avr32/uc3/serial.c
+++ b/libcpu/avr32/uc3/serial.c
@@ -160,7 +160,7 @@ static rt_size_t rt_serial_write (rt_device_t dev, rt_off_t pos, const void* buf
 			/* write data directly */
 			while (size)
 			{
-				while (usart_bw_write_char(uart->uart_device, (int) *ptr) != USART_SUCCESS);
+				usart_bw_write_char(uart->uart_device, (int) *ptr);
 
 				++ptr; --size;
 			}