[U-Boot] [PATCH 2/2] console: execute flush on uart when silent is removed

[Patrice Chotard]

From: Patrick Delaunay <patrick.delaunay at st.com>

Avoid to flush buffer when silent console is activated as the
console can be reactivate later, after relocation, when the env will
be updated with the saved one.

Solve issue (missing beginning of U-Boot trace) when:
- CONFIG_SILENT_CONSOLE is activated
- silent=1 is defined in default environment (CONFIG_EXTRA_ENV_SETTINGS)
- silent is removed in saved environment with:
      > env delete silent; env save

Only functional when PRE_CONSOLE_BUFFER is activated.

Signed-off-by: Patrick Delaunay <patrick.delaunay at st.com>
Signed-off-by: Patrice Chotard <patrice.chotard at st.com>
---

 common/console.c | 45 ++++++++++++++++++++++++++++++++++++---------
 1 file changed, 36 insertions(+), 9 deletions(-)

diff --git a/common/console.c b/common/console.c
index 7b45403bb3..d086feabb1 100644
--- a/common/console.c
+++ b/common/console.c
@@ -463,6 +463,11 @@ static void print_pre_console_buffer(int flushpoint)
 	char buf_out[CONFIG_PRE_CON_BUF_SZ + 1];
 	char *buf_in;
 
+#ifdef CONFIG_SILENT_CONSOLE
+	if (gd->flags & GD_FLG_SILENT)
+		return;
+#endif
+
 	buf_in = map_sysmem(CONFIG_PRE_CON_BUF_ADDR, CONFIG_PRE_CON_BUF_SZ);
 	if (gd->precon_buf_idx > CONFIG_PRE_CON_BUF_SZ)
 		in = gd->precon_buf_idx - CONFIG_PRE_CON_BUF_SZ;
@@ -511,8 +516,11 @@ void putc(const char c)
 		membuff_putbyte(&gd->console_out, c);
 #endif
 #ifdef CONFIG_SILENT_CONSOLE
-	if (gd->flags & GD_FLG_SILENT)
+	if (gd->flags & GD_FLG_SILENT) {
+		if (!(gd->flags & GD_FLG_DEVINIT))
+			pre_console_putc(c);
 		return;
+	}
 #endif
 
 #ifdef CONFIG_DISABLE_CONSOLE
@@ -559,8 +567,11 @@ void puts(const char *s)
 		membuff_put(&gd->console_out, s, strlen(s));
 #endif
 #ifdef CONFIG_SILENT_CONSOLE
-	if (gd->flags & GD_FLG_SILENT)
+	if (gd->flags & GD_FLG_SILENT) {
+		if (!(gd->flags & GD_FLG_DEVINIT))
+			pre_console_puts(s);
 		return;
+	}
 #endif
 
 #ifdef CONFIG_DISABLE_CONSOLE
@@ -720,14 +731,22 @@ int console_assign(int file, const char *devname)
 	return -1;
 }
 
-static void console_update_silent(void)
+/* return true if the 'silent' flag is removed */
+static bool console_update_silent(void)
 {
 #ifdef CONFIG_SILENT_CONSOLE
-	if (env_get("silent") != NULL)
+	if (env_get("silent")) {
 		gd->flags |= GD_FLG_SILENT;
-	else
+	} else {
+		unsigned long flags = gd->flags;
+
 		gd->flags &= ~GD_FLG_SILENT;
+
+		return !!(flags & GD_FLG_SILENT);
+	}
 #endif
+
+	return false;
 }
 
 int console_announce_r(void)
@@ -792,9 +811,13 @@ int console_init_r(void)
 #if CONFIG_IS_ENABLED(CONSOLE_MUX)
 	int iomux_err = 0;
 #endif
+	int flushpoint;
 
 	/* update silent for env loaded from flash (initr_env) */
-	console_update_silent();
+	if (console_update_silent())
+		flushpoint = PRE_CONSOLE_FLUSHPOINT1_SERIAL;
+	else
+		flushpoint = PRE_CONSOLE_FLUSHPOINT2_EVERYTHING_BUT_SERIAL;
 
 	/* set default handlers at first */
 	gd->jt->getc  = serial_getc;
@@ -872,7 +895,7 @@ done:
 	if ((stdio_devices[stdin] == NULL) && (stdio_devices[stdout] == NULL))
 		return 0;
 #endif
-	print_pre_console_buffer(PRE_CONSOLE_FLUSHPOINT2_EVERYTHING_BUT_SERIAL);
+	print_pre_console_buffer(flushpoint);
 	return 0;
 }
 
@@ -886,9 +909,13 @@ int console_init_r(void)
 	struct list_head *list = stdio_get_list();
 	struct list_head *pos;
 	struct stdio_dev *dev;
+	int flushpoint;
 
 	/* update silent for env loaded from flash (initr_env) */
-	console_update_silent();
+	if (console_update_silent())
+		flushpoint = PRE_CONSOLE_FLUSHPOINT1_SERIAL;
+	else
+		flushpoint = PRE_CONSOLE_FLUSHPOINT2_EVERYTHING_BUT_SERIAL;
 
 #ifdef CONFIG_SPLASH_SCREEN
 	/*
@@ -951,7 +978,7 @@ int console_init_r(void)
 	if ((stdio_devices[stdin] == NULL) && (stdio_devices[stdout] == NULL))
 		return 0;
 #endif
-	print_pre_console_buffer(PRE_CONSOLE_FLUSHPOINT2_EVERYTHING_BUT_SERIAL);
+	print_pre_console_buffer(flushpoint);
 	return 0;
 }
 
-- 
2.17.1