[PATCH 5.15 013/207] fbcon: Use correct erase colour for clearing in fbcon

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

5.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Zsolt Kajtar <soci@c64.rulez.org>

[ Upstream commit 892c788d73fe4a94337ed092cb998c49fa8ecaf4 ]

The erase colour calculation for fbcon clearing should use get_color instead
of attr_col_ec, like everything else. The latter is similar but is not correct.
For example it's missing the depth dependent remapping and doesn't care about
blanking.

The problem can be reproduced by setting up the background colour to grey
(vt.color=0x70) and having an fbcon console set to 2bpp (4 shades of gray).
Now the background attribute should be 1 (dark gray) on the console.

If the screen is scrolled when pressing enter in a shell prompt at the bottom
line then the new line is cleared using colour 7 instead of 1. That's not
something fillrect likes (at 2bbp it expect 0-3) so the result is interesting.

This patch switches to get_color with vc_video_erase_char to determine the
erase colour from attr_col_ec. That makes the latter function redundant as
no other users were left.

Use correct erase colour for clearing in fbcon

Signed-off-by: Zsolt Kajtar <soci@c64.rulez.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/video/fbdev/core/bitblit.c   |  5 ++--
 drivers/video/fbdev/core/fbcon.c     | 10 +++++---
 drivers/video/fbdev/core/fbcon.h     | 38 +---------------------------
 drivers/video/fbdev/core/fbcon_ccw.c |  5 ++--
 drivers/video/fbdev/core/fbcon_cw.c  |  5 ++--
 drivers/video/fbdev/core/fbcon_ud.c  |  5 ++--
 drivers/video/fbdev/core/tileblit.c  |  8 +++---
 7 files changed, 18 insertions(+), 58 deletions(-)

diff --git a/drivers/video/fbdev/core/bitblit.c b/drivers/video/fbdev/core/bitblit.c
index 8587c9da06700..42e681a78136a 100644
--- a/drivers/video/fbdev/core/bitblit.c
+++ b/drivers/video/fbdev/core/bitblit.c
@@ -59,12 +59,11 @@ static void bit_bmove(struct vc_data *vc, struct fb_info *info, int sy,
 }
 
 static void bit_clear(struct vc_data *vc, struct fb_info *info, int sy,
-		      int sx, int height, int width)
+		      int sx, int height, int width, int fg, int bg)
 {
-	int bgshift = (vc->vc_hi_font_mask) ? 13 : 12;
 	struct fb_fillrect region;
 
-	region.color = attr_bgcol_ec(bgshift, vc, info);
+	region.color = bg;
 	region.dx = sx * vc->vc_font.width;
 	region.dy = sy * vc->vc_font.height;
 	region.width = width * vc->vc_font.width;
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index b163b54b868e6..805a4745abd86 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -1249,7 +1249,7 @@ static void fbcon_clear(struct vc_data *vc, int sy, int sx, int height,
 {
 	struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
 	struct fbcon_ops *ops = info->fbcon_par;
-
+	int fg, bg;
 	struct fbcon_display *p = &fb_display[vc->vc_num];
 	u_int y_break;
 
@@ -1270,16 +1270,18 @@ static void fbcon_clear(struct vc_data *vc, int sy, int sx, int height,
 		fbcon_clear_margins(vc, 0);
 	}
 
+	fg = get_color(vc, info, vc->vc_video_erase_char, 1);
+	bg = get_color(vc, info, vc->vc_video_erase_char, 0);
 	/* Split blits that cross physical y_wrap boundary */
 
 	y_break = p->vrows - p->yscroll;
 	if (sy < y_break && sy + height - 1 >= y_break) {
 		u_int b = y_break - sy;
-		ops->clear(vc, info, real_y(p, sy), sx, b, width);
+		ops->clear(vc, info, real_y(p, sy), sx, b, width, fg, bg);
 		ops->clear(vc, info, real_y(p, sy + b), sx, height - b,
-				 width);
+				 width, fg, bg);
 	} else
-		ops->clear(vc, info, real_y(p, sy), sx, height, width);
+		ops->clear(vc, info, real_y(p, sy), sx, height, width, fg, bg);
 }
 
 static void fbcon_putcs(struct vc_data *vc, const unsigned short *s,
diff --git a/drivers/video/fbdev/core/fbcon.h b/drivers/video/fbdev/core/fbcon.h
index 0f16cbc99e6a4..3e1ec454b8aa3 100644
--- a/drivers/video/fbdev/core/fbcon.h
+++ b/drivers/video/fbdev/core/fbcon.h
@@ -57,7 +57,7 @@ struct fbcon_ops {
 	void (*bmove)(struct vc_data *vc, struct fb_info *info, int sy,
 		      int sx, int dy, int dx, int height, int width);
 	void (*clear)(struct vc_data *vc, struct fb_info *info, int sy,
-		      int sx, int height, int width);
+		      int sx, int height, int width, int fb, int bg);
 	void (*putcs)(struct vc_data *vc, struct fb_info *info,
 		      const unsigned short *s, int count, int yy, int xx,
 		      int fg, int bg);
@@ -118,42 +118,6 @@ static inline int mono_col(const struct fb_info *info)
 	return (~(0xfff << max_len)) & 0xff;
 }
 
-static inline int attr_col_ec(int shift, struct vc_data *vc,
-			      struct fb_info *info, int is_fg)
-{
-	int is_mono01;
-	int col;
-	int fg;
-	int bg;
-
-	if (!vc)
-		return 0;
-
-	if (vc->vc_can_do_color)
-		return is_fg ? attr_fgcol(shift,vc->vc_video_erase_char)
-			: attr_bgcol(shift,vc->vc_video_erase_char);
-
-	if (!info)
-		return 0;
-
-	col = mono_col(info);
-	is_mono01 = info->fix.visual == FB_VISUAL_MONO01;
-
-	if (attr_reverse(vc->vc_video_erase_char)) {
-		fg = is_mono01 ? col : 0;
-		bg = is_mono01 ? 0 : col;
-	}
-	else {
-		fg = is_mono01 ? 0 : col;
-		bg = is_mono01 ? col : 0;
-	}
-
-	return is_fg ? fg : bg;
-}
-
-#define attr_bgcol_ec(bgshift, vc, info) attr_col_ec(bgshift, vc, info, 0)
-#define attr_fgcol_ec(fgshift, vc, info) attr_col_ec(fgshift, vc, info, 1)
-
     /*
      *  Scroll Method
      */
diff --git a/drivers/video/fbdev/core/fbcon_ccw.c b/drivers/video/fbdev/core/fbcon_ccw.c
index 2789ace796342..9f4d65478554a 100644
--- a/drivers/video/fbdev/core/fbcon_ccw.c
+++ b/drivers/video/fbdev/core/fbcon_ccw.c
@@ -78,14 +78,13 @@ static void ccw_bmove(struct vc_data *vc, struct fb_info *info, int sy,
 }
 
 static void ccw_clear(struct vc_data *vc, struct fb_info *info, int sy,
-		     int sx, int height, int width)
+		     int sx, int height, int width, int fg, int bg)
 {
 	struct fbcon_ops *ops = info->fbcon_par;
 	struct fb_fillrect region;
-	int bgshift = (vc->vc_hi_font_mask) ? 13 : 12;
 	u32 vyres = GETVYRES(ops->p, info);
 
-	region.color = attr_bgcol_ec(bgshift,vc,info);
+	region.color = bg;
 	region.dx = sy * vc->vc_font.height;
 	region.dy = vyres - ((sx + width) * vc->vc_font.width);
 	region.height = width * vc->vc_font.width;
diff --git a/drivers/video/fbdev/core/fbcon_cw.c b/drivers/video/fbdev/core/fbcon_cw.c
index 86a254c1b2b7b..b18e31886da10 100644
--- a/drivers/video/fbdev/core/fbcon_cw.c
+++ b/drivers/video/fbdev/core/fbcon_cw.c
@@ -63,14 +63,13 @@ static void cw_bmove(struct vc_data *vc, struct fb_info *info, int sy,
 }
 
 static void cw_clear(struct vc_data *vc, struct fb_info *info, int sy,
-		     int sx, int height, int width)
+		     int sx, int height, int width, int fg, int bg)
 {
 	struct fbcon_ops *ops = info->fbcon_par;
 	struct fb_fillrect region;
-	int bgshift = (vc->vc_hi_font_mask) ? 13 : 12;
 	u32 vxres = GETVXRES(ops->p, info);
 
-	region.color = attr_bgcol_ec(bgshift,vc,info);
+	region.color = bg;
 	region.dx = vxres - ((sy + height) * vc->vc_font.height);
 	region.dy = sx *  vc->vc_font.width;
 	region.height = width * vc->vc_font.width;
diff --git a/drivers/video/fbdev/core/fbcon_ud.c b/drivers/video/fbdev/core/fbcon_ud.c
index 23bc045769d08..b6b074cfd9dc0 100644
--- a/drivers/video/fbdev/core/fbcon_ud.c
+++ b/drivers/video/fbdev/core/fbcon_ud.c
@@ -64,15 +64,14 @@ static void ud_bmove(struct vc_data *vc, struct fb_info *info, int sy,
 }
 
 static void ud_clear(struct vc_data *vc, struct fb_info *info, int sy,
-		     int sx, int height, int width)
+		     int sx, int height, int width, int fg, int bg)
 {
 	struct fbcon_ops *ops = info->fbcon_par;
 	struct fb_fillrect region;
-	int bgshift = (vc->vc_hi_font_mask) ? 13 : 12;
 	u32 vyres = GETVYRES(ops->p, info);
 	u32 vxres = GETVXRES(ops->p, info);
 
-	region.color = attr_bgcol_ec(bgshift,vc,info);
+	region.color = bg;
 	region.dy = vyres - ((sy + height) * vc->vc_font.height);
 	region.dx = vxres - ((sx + width) *  vc->vc_font.width);
 	region.width = width * vc->vc_font.width;
diff --git a/drivers/video/fbdev/core/tileblit.c b/drivers/video/fbdev/core/tileblit.c
index 2768eff247ba4..674ca6a410ec8 100644
--- a/drivers/video/fbdev/core/tileblit.c
+++ b/drivers/video/fbdev/core/tileblit.c
@@ -32,16 +32,14 @@ static void tile_bmove(struct vc_data *vc, struct fb_info *info, int sy,
 }
 
 static void tile_clear(struct vc_data *vc, struct fb_info *info, int sy,
-		       int sx, int height, int width)
+		       int sx, int height, int width, int fg, int bg)
 {
 	struct fb_tilerect rect;
-	int bgshift = (vc->vc_hi_font_mask) ? 13 : 12;
-	int fgshift = (vc->vc_hi_font_mask) ? 9 : 8;
 
 	rect.index = vc->vc_video_erase_char &
 		((vc->vc_hi_font_mask) ? 0x1ff : 0xff);
-	rect.fg = attr_fgcol_ec(fgshift, vc, info);
-	rect.bg = attr_bgcol_ec(bgshift, vc, info);
+	rect.fg = fg;
+	rect.bg = bg;
 	rect.sx = sx;
 	rect.sy = sy;
 	rect.width = width;
-- 
2.39.5