[ 3.5.y.z extended stable ] Patch "video: mxsfb: fix crash when unblanking the display" has been added to staging queue

[Herton Ronaldo Krzesinski]

This is a note to let you know that I have just added a patch titled

    video: mxsfb: fix crash when unblanking the display

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

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>From 12b012e4bbf85cfce419a2f9ede93b9db7ebf41e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lothar=20Wa=C3=9Fmann?= <LW at KARO-electronics.de>
Date: Thu, 22 Nov 2012 13:49:14 +0100
Subject: [PATCH] video: mxsfb: fix crash when unblanking the display
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

commit 6c1ecba8d84841277d68140ef485335d5be28485 upstream.

The VDCTRL4 register does not provide the MXS SET/CLR/TOGGLE feature.
The write in mxsfb_disable_controller() sets the data_cnt for the LCD
DMA to 0 which obviously means the max. count for the LCD DMA and
leads to overwriting arbitrary memory when the display is unblanked.

Signed-off-by: Lothar Waßmann <LW at KARO-electronics.de>
Acked-by: Juergen Beisert <jbe at pengutronix.de>
Tested-by: Lauri Hintsala <lauri.hintsala at bluegiga.net>
Signed-off-by: Shawn Guo <shawn.guo at linaro.org>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 drivers/video/mxsfb.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/video/mxsfb.c b/drivers/video/mxsfb.c
index abbe691..fc2c4381 100644
--- a/drivers/video/mxsfb.c
+++ b/drivers/video/mxsfb.c
@@ -367,7 +367,8 @@ static void mxsfb_disable_controller(struct fb_info *fb_info)
 		loop--;
 	}

-	writel(VDCTRL4_SYNC_SIGNALS_ON, host->base + LCDC_VDCTRL4 + REG_CLR);
+	reg = readl(host->base + LCDC_VDCTRL4);
+	writel(reg & ~VDCTRL4_SYNC_SIGNALS_ON, host->base + LCDC_VDCTRL4);

 	clk_disable_unprepare(host->clk);

--
1.7.9.5