tty: vt, cleanup and document con_scroll

Scrolling helpers scrup and scrdown both accept 'top' and 'bottom' as
unsigned int. Number of lines 'nr' is accepted as int, but all callers
pass down unsigned too. So change the type of 'nr' to unsigned too.
Now, promote unsigned int from the helpers up to the con_scroll
hook which actually accepted all those as signed int.

Next, the 'dir' parameter can have only two values and we define
constants for that: SM_UP and SM_DOWN. Switch them to enum and do
proper type checking on 'dir' too.

Finally, document the behaviour of the hook.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: <linux-fbdev@vger.kernel.org>
Cc: <linux-usb@vger.kernel.org>
Cc: <linux-parisc@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 8 insertions, 10 deletions

diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index b87f5cfdaea5..a44f5627b82a 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -164,8 +164,6 @@ static void fbcon_putcs(struct vc_data *vc, const unsigned short *s,
 			int count, int ypos, int xpos);
 static void fbcon_clear_margins(struct vc_data *vc, int bottom_only);
 static void fbcon_cursor(struct vc_data *vc, int mode);
-static int fbcon_scroll(struct vc_data *vc, int t, int b, int dir,
-			int count);
 static void fbcon_bmove(struct vc_data *vc, int sy, int sx, int dy, int dx,
 			int height, int width);
 static int fbcon_switch(struct vc_data *vc);
@@ -1795,15 +1793,15 @@ static inline void fbcon_softback_note(struct vc_data *vc, int t,
 	softback_curr = softback_in;
 }
 
-static int fbcon_scroll(struct vc_data *vc, int t, int b, int dir,
-			int count)
+static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
+		enum con_scroll dir, unsigned int count)
 {
 	struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
 	struct display *p = &fb_display[vc->vc_num];
 	int scroll_partial = info->flags & FBINFO_PARTIAL_PAN_OK;
 
 	if (fbcon_is_inactive(vc, info))
-		return -EINVAL;
+		return true;
 
 	fbcon_cursor(vc, CM_ERASE);
 
@@ -1831,7 +1829,7 @@ static int fbcon_scroll(struct vc_data *vc, int t, int b, int dir,
 							(b - count)),
 				    vc->vc_video_erase_char,
 				    vc->vc_size_row * count);
-			return 1;
+			return true;
 			break;
 
 		case SCROLL_WRAP_MOVE:
@@ -1903,7 +1901,7 @@ static int fbcon_scroll(struct vc_data *vc, int t, int b, int dir,
 							(b - count)),
 				    vc->vc_video_erase_char,
 				    vc->vc_size_row * count);
-			return 1;
+			return true;
 		}
 		break;
 
@@ -1922,7 +1920,7 @@ static int fbcon_scroll(struct vc_data *vc, int t, int b, int dir,
 							t),
 				    vc->vc_video_erase_char,
 				    vc->vc_size_row * count);
-			return 1;
+			return true;
 			break;
 
 		case SCROLL_WRAP_MOVE:
@@ -1992,10 +1990,10 @@ static int fbcon_scroll(struct vc_data *vc, int t, int b, int dir,
 							t),
 				    vc->vc_video_erase_char,
 				    vc->vc_size_row * count);
-			return 1;
+			return true;
 		}
 	}
-	return 0;
+	return false;
 }