fix(st-uart): skip console flush if UART is disabled
Check the USART_CR1_UE bit and if it is 0, the UART is not enabled,
or not clocked (but the read won't freeze the bus and will return 0).
In this case skip the console flush.
Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Change-Id: I5d1ef7e51612b4795e314b2f2da04a514b6c96a0
diff --git a/drivers/st/uart/aarch32/stm32_console.S b/drivers/st/uart/aarch32/stm32_console.S
index e3e0e67..d64a6cd 100644
--- a/drivers/st/uart/aarch32/stm32_console.S
+++ b/drivers/st/uart/aarch32/stm32_console.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2018-2022, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2023, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -234,11 +234,16 @@
cmp r0, #0
ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
+ /* Skip flush if UART is not enabled */
+ ldr r1, [r0, #USART_CR1]
+ ands r1, r1, #USART_CR1_UE
+ beq 1f
/* Check Transmit Data Register Empty */
txe_loop_3:
ldr r1, [r0, #USART_ISR]
tst r1, #USART_ISR_TXE
beq txe_loop_3
+1:
bx lr
endfunc console_stm32_core_flush