video: Let video_sync to return error value

This patch is preparation for follow up one to support cases where
synchronization can fail.

Suggested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/video/vidconsole-uclass.c

@@ -89,9 +89,7 @@ static int vidconsole_back(struct udevice *dev)
 		if (priv->ycur < 0)
 			priv->ycur = 0;
 	}
-	video_sync(dev->parent, false);
+	return video_sync(dev->parent, false);
-
-	return 0;
 }
 
 /* Move to a newline, scrolling the display if necessary */
@@ -101,7 +99,7 @@ static void vidconsole_newline(struct udevice *dev)
 	struct udevice *vid_dev = dev->parent;
 	struct video_priv *vid_priv = dev_get_uclass_priv(vid_dev);
 	const int rows = CONFIG_CONSOLE_SCROLL_LINES;
-	int i;
+	int i, ret;
 
 	priv->xcur_frac = priv->xstart_frac;
 	priv->ycur += priv->y_charsize;
@@ -116,7 +114,12 @@ static void vidconsole_newline(struct udevice *dev)
 	}
 	priv->last_ch = 0;
 
-	video_sync(dev->parent, false);
+	ret = video_sync(dev->parent, false);
+	if (ret) {
+#ifdef DEBUG
+		console_puts_select_stderr(true, "[vc err: video_sync]");
+#endif
+	}
 }
 
 static const struct vid_rgb colors[VID_COLOR_COUNT] = {
@@ -348,8 +351,15 @@ static void vidconsole_escape_char(struct udevice *dev, char ch)
 		parsenum(priv->escape_buf + 1, &mode);
 
 		if (mode == 2) {
+			int ret;
+
 			video_clear(dev->parent);
-			video_sync(dev->parent, false);
+			ret = video_sync(dev->parent, false);
+			if (ret) {
+#ifdef DEBUG
+				console_puts_select_stderr(true, "[vc err: video_sync]");
+#endif
+			}
 			priv->ycur = 0;
 			priv->xcur_frac = priv->xstart_frac;
 		} else {
@@ -565,7 +575,12 @@ static void vidconsole_putc(struct stdio_dev *sdev, const char ch)
 		console_puts_select_stderr(true, "[vc err: putc]");
 #endif
 	}
-	video_sync(dev->parent, false);
+	ret = video_sync(dev->parent, false);
+	if (ret) {
+#ifdef DEBUG
+		console_puts_select_stderr(true, "[vc err: video_sync]");
+#endif
+	}
 }
 
 static void vidconsole_puts(struct stdio_dev *sdev, const char *s)
@@ -582,7 +597,12 @@ static void vidconsole_puts(struct stdio_dev *sdev, const char *s)
 		console_puts_select_stderr(true, str);
 #endif
 	}
-	video_sync(dev->parent, false);
+	ret = video_sync(dev->parent, false);
+	if (ret) {
+#ifdef DEBUG
+		console_puts_select_stderr(true, "[vc err: video_sync]");
+#endif
+	}
 }
 
 /* Set up the number of rows and colours (rotated drivers override this) */
@@ -691,9 +711,7 @@ static int do_video_puts(struct cmd_tbl *cmdtp, int flag, int argc,
 	for (s = argv[1]; *s; s++)
 		vidconsole_put_char(dev, *s);
 
-	video_sync(dev->parent, false);
+	return video_sync(dev->parent, false);
-
-	return 0;
 }
 
 U_BOOT_CMD(

drivers/video/video-uclass.c

@@ -15,6 +15,7 @@
 #include <video_console.h>
 #include <asm/cache.h>
 #include <dm/lists.h>
+#include <dm/device_compat.h>
 #include <dm/device-internal.h>
 #include <dm/uclass-internal.h>
 #ifdef CONFIG_SANDBOX
@@ -172,7 +173,7 @@ void video_set_default_colors(struct udevice *dev, bool invert)
 }
 
 /* Flush video activity to the caches */
-void video_sync(struct udevice *vid, bool force)
+int video_sync(struct udevice *vid, bool force)
 {
 	/*
 	 * flush_dcache_range() is declared in common.h but it seems that some
@@ -196,17 +197,22 @@ void video_sync(struct udevice *vid, bool force)
 		last_sync = get_timer(0);
 	}
 #endif
+	return 0;
 }
 
 void video_sync_all(void)
 {
 	struct udevice *dev;
+	int ret;
 
 	for (uclass_find_first_device(UCLASS_VIDEO, &dev);
 	     dev;
 	     uclass_find_next_device(&dev)) {
-		if (device_active(dev))
+		if (device_active(dev)) {
-			video_sync(dev, true);
+			ret = video_sync(dev, true);
+			if (ret)
+				dev_dbg(dev, "Video sync failed\n");
+		}
 	}
 }
 

drivers/video/video_bmp.c

@@ -379,8 +379,5 @@ int video_bmp_display(struct udevice *dev, ulong bmp_image, int x, int y,
 	if (ret)
 		return log_ret(ret);
 
-	video_sync(dev, false);
+	return video_sync(dev, false);
-
-	return 0;
 }
-

include/video.h

@@ -155,11 +155,13 @@ int video_clear(struct udevice *dev);
  * @force:	True to force a sync even if there was one recently (this is
  *		very expensive on sandbox)
  *
+ * @return: 0 always
+ *
  * Some frame buffers are cached or have a secondary frame buffer. This
  * function syncs these up so that the current contents of the U-Boot frame
  * buffer are displayed to the user.
  */
-void video_sync(struct udevice *vid, bool force);
+int video_sync(struct udevice *vid, bool force);
 
 /**
  * video_sync_all() - Sync all devices' frame buffers with there hardware