fbcon: fix color generation for monochrome framebuffer

The current attr_fgcol_ec / attr_bgcol_ec macros do a simple shift of bits
to get the color from vc_video_erase_char.  For a monochrome display
however the attribute does not contain any color, only attribute bits.
Furthermore the reverse bit is lost because it is shifted out, the
resulting color is always 0.

This can bee seen on a monochrome console either directly or by setting it
to inverse mode via "setterm -inversescreen on" .  Text is written with
correct color, fb_fillrects from a bit_clear / bit_clear_margins will get
wrong colors.

Signed-off-by: Thomas Pfaff <tpfaff@pcs.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 43 insertions, 4 deletions

diff --git a/drivers/video/console/fbcon.h b/drivers/video/console/fbcon.h
index 8e6ef4bc7a5c..3706307e70ed 100644
--- a/drivers/video/console/fbcon.h
+++ b/drivers/video/console/fbcon.h
@@ -93,10 +93,6 @@ struct fbcon_ops {
         (((s) >> (fgshift)) & 0x0f)
 #define attr_bgcol(bgshift,s)    \
         (((s) >> (bgshift)) & 0x0f)
-#define attr_bgcol_ec(bgshift,vc) \
-        ((vc) ? (((vc)->vc_video_erase_char >> (bgshift)) & 0x0f) : 0)
-#define attr_fgcol_ec(fgshift,vc) \
-        ((vc) ? (((vc)->vc_video_erase_char >> (fgshift)) & 0x0f) : 0)
 
 /* Monochrome */
 #define attr_bold(s) \
@@ -108,6 +104,49 @@ struct fbcon_ops {
 #define attr_blink(s) \
         ((s) & 0x8000)
         
+#define mono_col(info)                                                  \
+        (~(0xfff << (max((info)->var.green.length,                      \
+                         max((info)->var.red.length,                    \
+                             (info)->var.blue.length)))) & 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);
+
 /* Font */
 #define REFCOUNT(fd)    (((int *)(fd))[-1])
 #define FNTSIZE(fd)     (((int *)(fd))[-2])