[PATCH] fbcon: Saner 16-color to 4-color conversion
Currently, the default linux 16-colors are converted to 4-colors by simply
dividing the values by 4. However, this is not necessarily correct since the
first 4 colors are converted to black, rendering them invisible.
So, for black, no conversion; for light colors, convert to gray, for normal
text color, no conversion, and for bright colors, convert to intense white.
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index 88bd8ef..bb4ea50 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -247,9 +247,26 @@
case 2:
/*
* Scale down 16-colors to 4 colors. Default 4-color palette
- * is grayscale.
+ * is grayscale. However, simply dividing the values by 4
+ * will not work, as colors 1, 2 and 3 will be scaled-down
+ * to zero rendering them invisible. So empirically convert
+ * colors to a sane 4-level grayscale.
*/
- color /= 4;
+ switch (color) {
+ case 0:
+ color = 0; /* black */
+ break;
+ case 1 ... 6:
+ color = 2; /* white */
+ break;
+ case 7 ... 8:
+ color = 1; /* gray */
+ break;
+ default:
+ color = 3; /* intense white */
+ break;
+ }
+ break;
case 3:
/*
* Last 8 entries of default 16-color palette is a more intense