fbcon: Fix accelerated fbdev scrolling while logo is still shown

There is no need to directly skip over to the SCROLL_REDRAW case while
the logo is still shown.

When using DRM, this change has no effect because the code will reach
the SCROLL_REDRAW case immediately anyway.

But if you run an accelerated fbdev driver and have
FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION enabled, console scrolling is
slowed down by factors so that it feels as if you use a 9600 baud
terminal.

So, drop those unnecessary checks and speed up fbdev console
acceleration during bootup.

Cc: stable@vger.kernel.org # v5.10+
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/YpkYxk7wsBPx3po+@p100

drivers/video/fbdev/core/fbcon.c

@@ -1758,8 +1758,6 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 	case SM_UP:
 		if (count > vc->vc_rows)	/* Maximum realistic size */
 			count = vc->vc_rows;
-		if (logo_shown >= 0)
-			goto redraw_up;
 		switch (fb_scrollmode(p)) {
 		case SCROLL_MOVE:
 			fbcon_redraw_blit(vc, info, p, t, b - t - count,
@@ -1848,8 +1846,6 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 	case SM_DOWN:
 		if (count > vc->vc_rows)	/* Maximum realistic size */
 			count = vc->vc_rows;
-		if (logo_shown >= 0)
-			goto redraw_down;
 		switch (fb_scrollmode(p)) {
 		case SCROLL_MOVE:
 			fbcon_redraw_blit(vc, info, p, b - 1, b - t - count,