fbdev: Garbage collect fbdev scrolling acceleration, part 1 (from TODO list)

Scroll acceleration is disabled in fbcon by hard-wiring p->scrollmode = SCROLL_REDRAW. Remove the obsolete code in fbcon.c and fbdev/core/ Signed-off-by: Claudio Suarez <cssk@net-c.es> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/YVXTYqszZix9TxjJ@gineta.localdomain

Author: Claudio Suarez

Documentation/gpu/todo.rst

@@ -314,16 +314,19 @@ Level: Advanced
 Garbage collect fbdev scrolling acceleration
 --------------------------------------------
 
-Scroll acceleration is disabled in fbcon by hard-wiring p->scrollmode =
-SCROLL_REDRAW. There's a ton of code this will allow us to remove:
+Scroll acceleration has been disabled in fbcon. Now it works as the old
+SCROLL_REDRAW mode. A ton of code was removed in fbcon.c and the hook bmove was
+removed from fbcon_ops.
+Remaining tasks:
 
-- lots of code in fbcon.c
-
-- a bunch of the hooks in fbcon_ops, maybe the remaining hooks could be called
+- a bunch of the hooks in fbcon_ops could be removed or simplified by calling
  directly instead of the function table (with a switch on p->rotate)
 
 - fb_copyarea is unused after this, and can be deleted from all drivers
 
+- after that, fb_copyarea can be deleted from fb_ops in include/linux/fb.h as
+ well as cfb_copyarea
+
 Note that not all acceleration code can be deleted, since clearing and cursor
 support is still accelerated, which might be good candidates for further
 deletion projects.

drivers/video/fbdev/core/bitblit.c

@@ -43,21 +43,6 @@ static void update_attr(u8 *dst, u8 *src, int attribute,
 }
 }
 
-static void bit_bmove(struct vc_data *vc, struct fb_info *info, int sy,
- int sx, int dy, int dx, int height, int width)
-{
-struct fb_copyarea area;
-
-area.sx = sx * vc->vc_font.width;
-area.sy = sy * vc->vc_font.height;
-area.dx = dx * vc->vc_font.width;
-area.dy = dy * vc->vc_font.height;
-area.height = height * vc->vc_font.height;
-area.width = width * vc->vc_font.width;
-
-info->fbops->fb_copyarea(info, &area);
-}
-
 static void bit_clear(struct vc_data *vc, struct fb_info *info, int sy,
  int sx, int height, int width)
 {
@@ -393,7 +378,6 @@ static int bit_update_start(struct fb_info *info)
 
 void fbcon_set_bitops(struct fbcon_ops *ops)
 {
-ops->bmove = bit_bmove;
 ops->clear = bit_clear;
 ops->putcs = bit_putcs;
 ops->clear_margins = bit_clear_margins;