Re: [PATCH] imxfb: correct location of callbacks in suspend andresume

[Uwe Kleine-König]

Hello,

On Wed, Jan 27, 2010 at 03:48:18PM -0800, Andrew Morton wrote:
> On Mon, 25 Jan 2010 16:37:34 +0100
> Uwe Kleine-K__nig  <u.kleine-koenig@xxxxxxxxxxxxxx> wrote:
> 
> > The probe function passes a pointer to a struct fb_info to
> > platform_set_drvdata, so don't interpret the return value of
> > platform_get_drvdata as a pointer to struct imxfb_info.
> > 
> > Signed-off-by: Uwe Kleine-K__nig <u.kleine-koenig@xxxxxxxxxxxxxx>
> > Acked-by: Sascha Hauer <kernel@xxxxxxxxxxxxxx>
> > Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> > ---
> >  drivers/video/imxfb.c |    6 ++++--
> >  1 files changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/video/imxfb.c b/drivers/video/imxfb.c
> > index 66358fa..b4b6dec 100644
> > --- a/drivers/video/imxfb.c
> > +++ b/drivers/video/imxfb.c
> > @@ -593,7 +593,8 @@ static int imxfb_activate_var(struct fb_var_screeninfo *var, struct fb_info *inf
> >   */
> >  static int imxfb_suspend(struct platform_device *dev, pm_message_t state)
> >  {
> > -	struct imxfb_info *fbi = platform_get_drvdata(dev);
> > +	struct fb_info *info = platform_get_drvdata(dev);
> > +	struct imxfb_info *fbi = info->par;
> >  
> >  	pr_debug("%s\n", __func__);
> >  
> > @@ -603,7 +604,8 @@ static int imxfb_suspend(struct platform_device *dev, pm_message_t state)
> >  
> >  static int imxfb_resume(struct platform_device *dev)
> >  {
> > -	struct imxfb_info *fbi = platform_get_drvdata(dev);
> > +	struct fb_info *info = platform_get_drvdata(dev);
> > +	struct imxfb_info *fbi = info->par;
> >  
> >  	pr_debug("%s\n", __func__);
> >  
> 
> What were the runtime effects of this bug?
For me it was that in the original imxfb_info *fbi backlight_power was
NULL but in imxfb_suspend it was 4 resulting in an oops as imxfb_suspend
calls imxfb_disable_controller(fbi) which in turn has

	if (fbi->backlight_power)
		fbi->backlight_power(0);

.

Best regards
Uwe

-- 
Pengutronix e.K.                              | Uwe Kleine-König            |
Industrial Linux Solutions                    | http://www.pengutronix.de/  |
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