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

Lothar Waßmann LW at KARO-electronics.de
Wed Dec 21 02:27:10 EST 2011


Hi,

Lothar Waßmann writes:
> 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>
> ---
>  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
> 
Ping. Any comments on this?


Lothar Waßmann
-- 
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