[PATCH] fbdev: Fix greater than 1 bit monochrome color handling

Currently, fbcon assumes that the visual FB_VISUAL_MONO* is always 1 bit.
According to Geert, there are old hardware where it's possible to have
monochrome at 8-bit, but has only 2 colors, black - 0x00 and white - 0xff.
Fix color handlers (fb_get_color_depth, and get_color) for this special case.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 28 insertions, 13 deletions

diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index a8eee79e117d..a815f5e2fcb5 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -62,16 +62,26 @@ int num_registered_fb;
  * Helpers
  */
 
-int fb_get_color_depth(struct fb_var_screeninfo *var)
+int fb_get_color_depth(struct fb_var_screeninfo *var,
+                       struct fb_fix_screeninfo *fix)
 {
-        if (var->green.length == var->blue.length &&
-            var->green.length == var->red.length &&
-            !var->green.offset && !var->blue.offset &&
-            !var->red.offset)
-                return var->green.length;
-        else
-                return (var->green.length + var->red.length +
-                        var->blue.length);
+        int depth = 0;
+
+        if (fix->visual == FB_VISUAL_MONO01 ||
+            fix->visual == FB_VISUAL_MONO10)
+                depth = 1;
+        else {
+                if (var->green.length == var->blue.length &&
+                    var->green.length == var->red.length &&
+                    var->green.offset == var->blue.offset &&
+                    var->green.offset == var->red.offset)
+                        depth = var->green.length;
+                else
+                        depth = var->green.length + var->red.length +
+                                var->blue.length;
+        }
+
+        return depth;
 }
 EXPORT_SYMBOL(fb_get_color_depth);
 
@@ -249,13 +259,18 @@ static void fb_set_logo(struct fb_info *info,
                                const struct linux_logo *logo, u8 *dst,
                                int depth)
 {
-        int i, j, k, fg = 1;
+        int i, j, k;
         const u8 *src = logo->data;
-        u8 d, xor = (info->fix.visual == FB_VISUAL_MONO01) ? 0xff : 0;
+        u8 xor = (info->fix.visual == FB_VISUAL_MONO01) ? 0xff : 0;
+        u8 fg = 1, d;
 
-        if (fb_get_color_depth(&info->var) == 3)
+        if (fb_get_color_depth(&info->var, &info->fix) == 3)
                 fg = 7;
 
+        if (info->fix.visual == FB_VISUAL_MONO01 ||
+            info->fix.visual == FB_VISUAL_MONO10)
+                fg = ~((u8) (0xfff << info->var.green.length));
+
         switch (depth) {
         case 4:
                 for (i = 0; i < logo->height; i++)
@@ -318,7 +333,7 @@ static struct logo_data {
 
 int fb_prepare_logo(struct fb_info *info)
 {
-        int depth = fb_get_color_depth(&info->var);
+        int depth = fb_get_color_depth(&info->var, &info->fix);
 
         memset(&fb_logo, 0, sizeof(struct logo_data));