[RADEON]: Fix blanking return value.

If you'll recall, over a year ago, I pointed out that the current
Radeon driver erroneously returns -EINVAL for valid blanking codes,
here is a link to that thread:

http://lkml.org/lkml/2006/1/28/6

No other driver does this, and it confuses the X server into thinking
that the device does not support blanking properly.

I looked again and there is simply no reason for the Radeon driver to
return -EINVAL for FB_BLANK_NORMAL. It claims it wants to do this in
order to convince fbcon to blank in software, right here:

if (fb_blank(info, blank))
fbcon_generic_blank(vc, info, blank);

to software blank the screen. But it only causes that to happen
in the FB_BLANK_NORMAL case.

That makes no sense because the Radeon code does this:

val |= CRTC_DISPLAY_DIS;

in the FB_BLANK_NORMAL case so should be blanking the hardware, and
there is therefore no reason to SW blank by returning -EINVAL.

Signed-off-by: David S. Miller <[e-mail]>
Acked-by: Antonino Daplas <[e-mail]>

drivers/video/aty/radeon_base.c

···
 		break;
 	}
 
-	/* let fbcon do a soft blank for us */
-	return (blank == FB_BLANK_NORMAL) ? -EINVAL : 0;
+	return 0;
 }
 
 static int radeonfb_blank (int blank, struct fb_info *info)