On Tuesday, April 16, 2013 8:07 AM, Andrew Morton wrote:
>
> On Thu, 11 Apr 2013 13:24:50 -0700 Andrew Bresticker <abrestic@xxxxxxxxxxxx> wrote:
>
> > Platform LCD devices may need to do some device-specific
> > initialization before they can be used (regulator or GPIO setup,
> > for example), but currently the driver does not support any way of
> > doing this. This patch adds a probe() callback to plat_lcd_data
> > which platform LCD devices can set to indicate that device-specific
> > initialization is needed.
> >
> > index 17a6b83..f46180e 100644
> > --- a/drivers/video/backlight/platform_lcd.c
> > +++ b/drivers/video/backlight/platform_lcd.c
> > @@ -86,6 +86,12 @@ static int platform_lcd_probe(struct platform_device *pdev)
> > return -EINVAL;
> > }
> >
> > + if (pdata->probe) {
> > + err = pdata->probe(pdata);
> > + if (err)
> > + return err;
> > + }
> > +
> > plcd = devm_kzalloc(&pdev->dev, sizeof(struct platform_lcd),
> > GFP_KERNEL);
> > if (!plcd) {
> > diff --git a/include/video/platform_lcd.h b/include/video/platform_lcd.h
> > index ad3bdfe..23864b2 100644
> > --- a/include/video/platform_lcd.h
> > +++ b/include/video/platform_lcd.h
> > @@ -15,6 +15,7 @@ struct plat_lcd_data;
> > struct fb_info;
> >
> > struct plat_lcd_data {
> > + int (*probe)(struct plat_lcd_data *);
> > void (*set_power)(struct plat_lcd_data *, unsigned int power);
> > int (*match_fb)(struct plat_lcd_data *, struct fb_info *);
> > };
>
> Sigh. I see that this entire interface has been lovingly undocumented.
> It's an invitation for us to grow bugs, incompatibilities, leaks, etc.
>
> Possible example: what happens if pdata->probe does some resource
> allocation or device initialisation which should be backed out if, say,
> platform_lcd_probe() later fails?
Hi Andrew,
I agree with you.
Indeed, the documentation is necessary.
Andrew Bresticker,
Would you make the document?
It would be very helpful.
Best regards,
Jingoo Han
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