vt: do not update when the console is blanked

vt.c DO_UPDATE macro checks if the console is visible but doesn't check if
the console is blanked.

In fact updating fbcon while the console is blanked is not only
unnecessary but can even cause screen corruption.

Therefore I am adding a simple check on console_blanked in DO_UPDATE.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index ab53a1d4d89504eb1dc6fdefaadbf027bf8482e4..cb8c90da3934fa60bb08b47460271a2135878b68 100644 (file)
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -261,7 +261,7 @@ static void notify_update(struct vc_data *vc)
 #ifdef VT_BUF_VRAM_ONLY
 #define DO_UPDATE(vc)  0
 #else
-#define DO_UPDATE(vc)  CON_IS_VISIBLE(vc)
+#define DO_UPDATE(vc)  (CON_IS_VISIBLE(vc) && !console_blanked)
 #endif
 
 static inline unsigned short *screenpos(struct vc_data *vc, int offset, int viewed)