Update fixed screen info after changing format or resolution

The line length field can change after changing the format or the
resolution. Re-read fixed screen info from the device.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 28 insertions, 11 deletions

diff --git a/fbdev.c b/fbdev.c
index 205ab3c..578e67a 100644
--- a/fbdev.c
+++ b/fbdev.c
@@ -316,6 +316,25 @@ static void fb_unmap_memory(struct device *dev)
  * Open/close
  */
 
+static int fb_update_info(struct device *dev)
+{
+	int ret;
+
+	ret = ioctl(dev->fd, FBIOGET_FSCREENINFO, &dev->fix_info);
+	if (ret < 0) {
+		printf("Error updating fixed screen info.\n");
+		return ret;
+	}
+
+	ret = ioctl(dev->fd, FBIOGET_VSCREENINFO, &dev->var_info);
+	if (ret < 0) {
+		printf("Error updating variable screen info.\n");
+		return ret;
+	}
+
+	return 0;
+}
+
 /*
  * fb_open - Open a frame buffer device
  * @dev: FB device
@@ -338,18 +357,10 @@ static int fb_open(struct device *dev, const char *devname)
 		return dev->fd;
 	}
 
-	ret = ioctl(dev->fd, FBIOGET_FSCREENINFO, &dev->fix_info);
-	if (ret < 0) {
-		printf("Error opening device %s: unable to get fixed screen "
-			"info.\n", devname);
-		close(dev->fd);
-		return ret;
-	}
-
-	ret = ioctl(dev->fd, FBIOGET_VSCREENINFO, &dev->var_info);
+	ret = fb_update_info(dev);
 	if (ret < 0) {
-		printf("Error opening device %s: unable to get variable screen "
-			"info.\n", devname);
+		printf("Error opening device %s: unable to get screen info.\n",
+			devname);
 		close(dev->fd);
 		return ret;
 	}
@@ -497,6 +508,9 @@ static int fb_set_format(struct device *dev, unsigned int bpp)
 
 	fb_print_var(dev, &var_info);
 
+	/* Fixed screen information might have changed, re-read it. */
+	fb_update_info(dev);
+
 	return 0;
 }
 
@@ -552,6 +566,9 @@ static int fb_set_resolution(struct device *dev, int xres, int yres,
 
 	fb_print_var(dev, &var_info);
 
+	/* Fixed screen information might have changed, re-read it. */
+	fb_update_info(dev);
+
 	return 0;
 }