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    SubjectRe: [BUGFIX] video/mxsfb: fix crash when unblanking the display
    Hi Lothar,
    > 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@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
    I've encountered this problem to, and i can confirm your patch fixed it.
    The VDCTRL4 register has no CLR feature.

    Regards,

    --
    Robin van der Gracht
    Protonic Holland.
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    fax.: +31 (0) 229 210930
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