[AD] fbcon driver color depth

[Milan Mimica <milan.mimica@xxxxxxxxxx>]

A call to set_gfx_mode(GFX_FBCON, ...) will crash if color depth 
unsupported by the framebuffer was selected. I'm using vesafb that can't 
change color depth selected at boot time.

Graphic mode is set in src/linux/fbcon.c, line 334:
/* try to set the mode */
if (ioctl(fbfd, FBIOPUT_VSCREENINFO, &my_mode) == 0)
   goto got_a_nice_mode;

Apparently, setting a mode with unsupported color depth will not fail. 
It will just modify 'my_mode' to the mode that was actually set. I 
assume that other fields in 'my_mode' are also corrected. I couldn't 
find any documentation that would confirm that. I couldn't find any 
documentation at all for that matter.

Attached is a fix that is rather simple: update allegro to the actual 
color depth and continue, using 'my_mode.bits_per_pixel' instead of 
requested 'color_depth'.

Any opinions?


--
Milan Mimica
http://sparklet.sf.net

Index: src/linux/fbcon.c
===================================================================
--- src/linux/fbcon.c	(revision 7682)
+++ src/linux/fbcon.c	(working copy)
@@ -331,8 +331,10 @@
 	 continue;
 
       /* try to set the mode */
-      if (ioctl(fbfd, FBIOPUT_VSCREENINFO, &my_mode) == 0)
+      if (ioctl(fbfd, FBIOPUT_VSCREENINFO, &my_mode) == 0) {
+	 set_color_depth(my_mode.bits_per_pixel);
 	 goto got_a_nice_mode;
+      }
    }
 
    /* oops! */
@@ -386,11 +388,12 @@
       v_w = w;
       v_h = h;
 
-      p += (my_mode.xres-w)/2 * BYTES_PER_PIXEL(color_depth) + 
+      p += (my_mode.xres-w)/2 * BYTES_PER_PIXEL(my_mode.bits_per_pixel) + 
 	   (my_mode.yres-h)/2 * stride;
    }
 
-   b = _make_bitmap(v_w, v_h, (unsigned long)p, &gfx_fbcon, color_depth, stride);
+   b = _make_bitmap(v_w, v_h, (unsigned long)p, &gfx_fbcon,
+		    my_mode.bits_per_pixel, stride);
    if (!b) {
       ioctl(fbfd, FBIOPUT_VSCREENINFO, &orig_mode);
       munmap(fbaddr, fix_info.smem_len);
@@ -413,7 +416,7 @@
    gfx_fbcon.desc = fb_desc;
 
    /* set up the truecolor pixel format */
-   switch (color_depth) {
+   switch (my_mode.bits_per_pixel) {
 
       #ifdef ALLEGRO_COLOR16