[BUGFIX] video/mxsfb: fix crash when unblanking the display

From: Lothar WaÃmann
Date: Tue Dec 06 2011 - 07:27:09 EST


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 WaÃmann <LW@xxxxxxxxxxxxxxxxxxx>
---
drivers/video/mxsfb.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/video/mxsfb.c b/drivers/video/mxsfb.c
index d837d63..03cb95a 100644
--- a/drivers/video/mxsfb.c
+++ b/drivers/video/mxsfb.c
@@ -366,7 +366,8 @@ 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(host->clk);

--
1.5.6.5

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