From 4dfee50a0be8d61c79928f7bb11a4b77c485aea1 Mon Sep 17 00:00:00 2001
From: robert-hh <robert@hammelrath.com>
Date: Sun, 9 Mar 2025 11:39:12 +0100
Subject: [PATCH] samd/machine_uart: Fix lock-up in loopback mode if read
 buffer is full.

Signed-off-by: robert-hh <robert@hammelrath.com>
---
 ports/samd/machine_uart.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/ports/samd/machine_uart.c b/ports/samd/machine_uart.c
index 85a81660ca..5be38e961c 100644
--- a/ports/samd/machine_uart.c
+++ b/ports/samd/machine_uart.c
@@ -156,7 +156,8 @@ void common_uart_irq_handler(int uart_id) {
                 }
             }
             #endif
-        } else if (uart->USART.INTFLAG.bit.DRE != 0) {
+        }
+        if (uart->USART.INTFLAG.bit.DRE != 0) {
             #if MICROPY_HW_UART_TXBUF
             // handle the outgoing data
             if (ringbuf_avail(&self->write_buffer) > 0) {