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

[Robin van der Gracht]

Hi Lothar,
> Hi,
>
> Lothar WaÃmann 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 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
> Ping. Any comments on this?
>
>
> Lothar WaÃmann
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.
tel.: +31 (0) 229 212928
fax.: +31 (0) 229 210930
Factorij 36 / 1689 AL Zwaag

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