This patch would do checking on device tree to ensure the UART exist
in the system and ready for console before setting have_console to true.
This is required to avoid unexpected behavior such as hang during UART
initialization.
Signed-off-by: Tien Fong Chee <tfc...@altera.com>
Cc: Dinh Nguyen <dingu...@opensource.altera.com>
Cc: Dinh Nguyen <dinh.li...@gmail.com>
Cc: ChinLiang <cl...@altera.com>
Cc: Thomas Chou <tho...@wytron.com.tw>
Cc: Simon Glass <s...@chromium.org>
Cc: Marek Vasut <ma...@denx.de>
---
common/console.c | 11 ++++---
common/spl/spl.c | 3 +-
drivers/serial/serial.c | 58 +++++++++++++++++++++++++++++++++++-
include/asm-generic/global_data.h | 1 +
include/serial.h | 1 +
5 files changed, 66 insertions(+), 8 deletions(-)
diff --git a/common/console.c b/common/console.c
index 12293f3..c37486c 100644
--- a/common/console.c
+++ b/common/console.c
@@ -690,14 +690,15 @@ int console_assign(int file, const char *devname)
/* Called before relocation - use serial functions */
int console_init_f(void)
{
- gd->have_console = 1;
-
+ if(gd->uart_ready_for_console) {
+ gd->have_console = 1;
#ifdef CONFIG_SILENT_CONSOLE
- if (getenv("silent") != NULL)
- gd->flags |= GD_FLG_SILENT;
+ if (getenv("silent") != NULL)
+ gd->flags |= GD_FLG_SILENT;
#endif
- print_pre_console_buffer(PRE_CONSOLE_FLUSHPOINT1_SERIAL);
+ print_pre_console_buffer(PRE_CONSOLE_FLUSHPOINT1_SERIAL);
+ }
return 0;
}
diff --git a/common/spl/spl.c b/common/spl/spl.c
index b7ec333..c18827d 100644
--- a/common/spl/spl.c
+++ b/common/spl/spl.c
@@ -488,7 +488,8 @@ void preloader_console_init(void)
serial_init(); /* serial communications setup */
- gd->have_console = 1;
+ if(gd->uart_ready_for_console)
+ gd->have_console = 1;
puts("\nU-Boot SPL " PLAIN_VERSION " (" U_BOOT_DATE " - " \
U_BOOT_TIME ")\n");
diff --git a/drivers/serial/serial.c b/drivers/serial/serial.c
index f1bd15b..95690e0 100644
--- a/drivers/serial/serial.c
+++ b/drivers/serial/serial.c
@@ -35,6 +35,51 @@ static void serial_null(void)
}
/**
+ * uart_console_null() - This empty function would be used if UART console
checking
+ * function is not compiled into U-boot.
+ *
+ * This routine returns true to indicate UART is ready for console by default.
+ * The driver is aliased to this empty function in case
+ * the driver is not compiled into U-Boot.
+ */
+static int uart_console_null(void)
+{
+ return 1;
+}
+
+/**
+ * uart_console_func() - Forward declare of driver checking UART is ready based
+ * on device tree.
+ * @name: Name of driver which checking UART is ready based on device
tree .
+ *
+ * This macro expands onto forward declaration of a driver checking
+ * UART is ready based on device tree, which allows own assigned function name.
+ * The declaration is made weak and aliases to uart_console_null() so in case
+ * the driver is not compiled in, the function is still declared and can
+ * be used, but aliases to uart_console_null() and thus is optimized away.
+ */
+#define uart_console_func(name) \
+ int name(const void *blob)
\
+ __attribute__((weak, alias("uart_console_null")));
+
+uart_console_func(is_default_uart_console_true);
+
+/**
+ * is_uart_console_true() - Common function to abstract the specific UART
+ * console checking function.
+ *
+ * This is common interface for specific UART console checking function.
+ */
+int is_uart_console_true(const void *blob)
+{
+ int ret = 0;
+
+ ret |= is_default_uart_console_true(blob);
+
+ return ret;
+}
+
+/**
* on_baudrate() - Update the actual baudrate when the env var changes
*
* This will check for a valid baudrate and only apply it if valid.
@@ -415,8 +460,17 @@ static struct serial_device *get_current(void)
*/
int serial_init(void)
{
- gd->flags |= GD_FLG_SERIAL_READY;
- return get_current()->start();
+ if(is_uart_console_true(gd->fdt_blob))
+ gd->uart_ready_for_console = 1;
+ else
+ gd->uart_ready_for_console = 0;
+
+ if(gd->uart_ready_for_console) {
+ gd->flags |= GD_FLG_SERIAL_READY;
+ return get_current()->start();
+ }
+
+ return 0;
}
/**
diff --git a/include/asm-generic/global_data.h
b/include/asm-generic/global_data.h
index a6d1d2a..1cb7ef7 100644
--- a/include/asm-generic/global_data.h
+++ b/include/asm-generic/global_data.h
@@ -44,6 +44,7 @@ typedef struct global_data {
#ifdef CONFIG_BOARD_TYPES
unsigned long board_type;
#endif
+ unsigned long uart_ready_for_console; /* UART ready to support console
*/
unsigned long have_console; /* serial_init() was called */
#ifdef CONFIG_PRE_CONSOLE_BUFFER
unsigned long precon_buf_idx; /* Pre-Console buffer index */
diff --git a/include/serial.h b/include/serial.h
index 47332c5..a95bf70 100644
--- a/include/serial.h
+++ b/include/serial.h
@@ -50,6 +50,7 @@ extern void serial_initialize(void);
extern void serial_stdio_init(void);
extern int serial_assign(const char *name);
extern void serial_reinit_all(void);
+extern int is_uart_console_true(const void *blob);
/* For usbtty */
#ifdef CONFIG_USB_TTY
--
1.7.7.4
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