[PATCH] framebuffer: cmap-setting return values

A set of 3 small bugfixes, all of which are related to bogus return values
of fb colormap-setting functions.

First, fb_alloc_cmap returns -1 if memory allocation fails. This is a hard
condition to reproduce since you'd have to be really low on memory, but from
studying the contexts in which it is called, I think this function should be
returning a negative errno, and the -1 will be seen as an EPERM. Switching it
to -ENOMEM makes sense.

Second, the store_cmap function which is called for writes to
/sys/class/graphics/fb0/color_map returns 0 for success, but it should be
returning the count of bytes written since its return value ends up in
userspace as the result of the write() syscall.

Third, radeonfb returns 1 instead of a negative errno when FBIOPUTCMAP is
called with an oversized colormap.  This is seen in userspace as a return
value of 1 from the ioctl() syscall with errno left unchanged.  A more
useful return value would be -EINVAL.

Signed-off-by: Alan Curry <pacman@TheWorld.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/video/fbcmap.c

@@ -85,7 +85,7 @@ static struct fb_cmap default_16_colors = {
  *	Allocates memory for a colormap @cmap.  @len is the
  *	number of entries in the palette.
  *
- *	Returns -1 errno on error, or zero on success.
+ *	Returns negative errno on error, or zero on success.
  *
  */
 
@@ -116,7 +116,7 @@ int fb_alloc_cmap(struct fb_cmap *cmap, int len, int transp)
 
 fail:
     fb_dealloc_cmap(cmap);
-    return -1;
+    return -ENOMEM;
 }
 
 /**