On 07/26/2016 12:55 PM, Tien Fong Chee wrote:
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.
Can you elaborate on the issue in more depth ? This patch looks like some sort of workaround/hack.
Signed-off-by: Tien Fong Chee tfchee@altera.com Cc: Dinh Nguyen dinguyen@opensource.altera.com Cc: Dinh Nguyen dinh.linux@gmail.com Cc: ChinLiang clsee@altera.com Cc: Thomas Chou thomas@wytron.com.tw Cc: Simon Glass sjg@chromium.org Cc: Marek Vasut marex@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