3 files changed, 13 insertions, 0 deletions
diff --git a/src/soc/amd/picasso/include/soc/southbridge.h b/src/soc/amd/picasso/include/soc/southbridge.h
index 5bae754cf6..63c9876fce 100644
--- a/src/soc/amd/picasso/include/soc/southbridge.h
+++ b/src/soc/amd/picasso/include/soc/southbridge.h
@@ -280,6 +280,7 @@ void southbridge_init(void *chip_info);
 void fch_pre_init(void);
 void fch_early_init(void);
 void set_uart_config(int idx);
+void clear_uart_legacy_config(void);
 
 /* Initialize all the i2c buses that are marked with early init. */
 void i2c_soc_early_init(void);
diff --git a/src/soc/amd/picasso/southbridge.c b/src/soc/amd/picasso/southbridge.c
index a18f5a37bd..d2904d894b 100644
--- a/src/soc/amd/picasso/southbridge.c
+++ b/src/soc/amd/picasso/southbridge.c
@@ -226,6 +226,13 @@ void fch_pre_init(void)
 	sb_enable_legacy_io();
 	enable_aoac_devices();
 	sb_reset_i2c_slaves();
+
+	/*
+	 * On reset Range_0 defaults to enabled. We want to start with a clean
+	 * slate to not have things unexpectedly enabled.
+	 */
+	clear_uart_legacy_config();
+
 	if (CONFIG(PICASSO_UART))
 		set_uart_config(CONFIG_UART_FOR_CONSOLE);
 }
diff --git a/src/soc/amd/picasso/uart.c b/src/soc/amd/picasso/uart.c
index 84d6982968..6439efb251 100644
--- a/src/soc/amd/picasso/uart.c
+++ b/src/soc/amd/picasso/uart.c
@@ -38,6 +38,11 @@ uintptr_t uart_platform_base(int idx)
 	return uart_info[idx].base;
 }
 
+void clear_uart_legacy_config(void)
+{
+	write16((void *)FCH_UART_LEGACY_DECODE, 0);
+}
+
 void set_uart_config(int idx)
 {
 	uint32_t uart_ctrl;