Fix the graphic corruption issue on IA64 machines

VGA console driver can misunderstand the current mode(Text/Graphic) under
"disable console blanking" setting.  When "disable console blank" is set
(blankinterval=0), "do_unblank_screen()" function returns without changing
"blank_state", and when "blank_state" is "blank_off", "do_blank_screen()
function returns without invoking sw->con_blank() function.  That's why VGA
console driver can misunderstand the current mode.

Signed-off-by: Nobuhiro Tachino <ntachino@redhat.com>
Signed-off-by: Taku Izumi <izumi2005@soft.fujitsu.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Acked-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/vt.c

@@ -3506,20 +3506,22 @@ void do_blank_screen(int entering_gfx)
 		}
 		return;
 	}
-	if (blank_state != blank_normal_wait)
-		return;
-	blank_state = blank_off;
 
 	/* entering graphics mode? */
 	if (entering_gfx) {
 		hide_cursor(vc);
 		save_screen(vc);
 		vc->vc_sw->con_blank(vc, -1, 1);
 		console_blanked = fg_console + 1;
+		blank_state = blank_off;
 		set_origin(vc);
 		return;
 	}
 
+	if (blank_state != blank_normal_wait)
+		return;
+	blank_state = blank_off;
+
 	/* don't blank graphics */
 	if (vc->vc_mode != KD_TEXT) {
 		console_blanked = fg_console + 1;