[PATCH v2 1/2] board: atmel: sama5d2_wlsom1_ek: Fix spurious serial output

Fabio Estevam festevam at gmail.com
Fri Apr 4 13:39:18 CEST 2025


From: Fabio Estevam <festevam at denx.de>

Currently, there are always some spurious characters showing up
right before SPL banner is shown:

RomBOOT
���=������
U-Boot SPL 2025.04-rc5-00023-g9ed4e2c45f25 (Apr 03 2025 - 23:23:17 -0300)
Trying to boot from MMC1

<debug_uart>
...

The reason for the spurious characters is that the UART0 clock is
being enabled too early, prior to adjusting its correct frequency.

Fix the problem by removing the early UART0 clock enablement in C code.

SPL DM code will adjust the correct UART0 clock frequency and then enable
it at the appropriate time.

Signed-off-by: Fabio Estevam <festevam at denx.de>
---
Changes since v1:
- Make the minimal change to fix the spurious characters. Improve
the explanation in the commit log.

 board/atmel/sama5d27_wlsom1_ek/sama5d27_wlsom1_ek.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/board/atmel/sama5d27_wlsom1_ek/sama5d27_wlsom1_ek.c b/board/atmel/sama5d27_wlsom1_ek/sama5d27_wlsom1_ek.c
index 04de1257eca0..ff5e51ee3926 100644
--- a/board/atmel/sama5d27_wlsom1_ek/sama5d27_wlsom1_ek.c
+++ b/board/atmel/sama5d27_wlsom1_ek/sama5d27_wlsom1_ek.c
@@ -45,8 +45,6 @@ static void board_uart0_hw_init(void)
 {
 	atmel_pio4_set_c_periph(AT91_PIO_PORTB, 26, ATMEL_PIO_PUEN_MASK);	/* URXD0 */
 	atmel_pio4_set_c_periph(AT91_PIO_PORTB, 27, 0);				/* UTXD0 */
-
-	at91_periph_clk_enable(ATMEL_ID_UART0);
 }
 
 void board_debug_uart_init(void)
-- 
2.34.1



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