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>

1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index 45b33cf97643..edb7002a3216 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -3506,9 +3506,6 @@ 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) {
@@ -3516,10 +3513,15 @@ void do_blank_screen(int entering_gfx)
                 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;