Re: [PATCH] backlight: pwm: reject legacy pwm request for device defined in dt

[Lee Jones <lee.jones@linaro.org>]

On Tue, 22 Sep 2015, Lee Jones wrote:

> On Sun, 14 Jun 2015, Vladimir Zapolskiy wrote:
> 
> > Platform PWM backlight data provided by board's device tree should be
> > complete enough to successfully request a pwm device using pwm_get()
> > API. This change fixes a bug, when an arbitrary (first found) PWM is
> > connected to a "pwm-backlight" compatible device, when explicit PWM
> > device reference is not given.
> > 
> > Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt
> > already describes "pwms" as a required property, instead of blind
> > selection of a potentially wrong PWM reject legacy PWM device
> > registration request, leave legacy API only for non-dt cases.
> > 
> > Based on initial implementation done by Dmitry Eremin-Solenikov.
> > 
> > Reported-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
> > Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
> > Acked-by: Thierry Reding <thierry.reding@gmail.com>
> > ---
> >  drivers/video/backlight/pwm_bl.c | 13 +++++++------
> >  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> Applied, thanks.

Slight change of plan, as the patch does not apply.

Please rebase it on top of the backlight tree and resubmit with my
Ack.

> > diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> > index 57cb9ec..9991cdb 100644
> > --- a/drivers/video/backlight/pwm_bl.c
> > +++ b/drivers/video/backlight/pwm_bl.c
> > @@ -271,15 +271,16 @@ static int pwm_backlight_probe(struct platform_device *pdev)
> >  	}
> >  
> >  	pb->pwm = devm_pwm_get(&pdev->dev, NULL);
> > -	if (IS_ERR(pb->pwm)) {
> > +	if (IS_ERR(pb->pwm) && !pdev->dev.of_node) {
> >  		dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n");
> >  		pb->legacy = true;
> >  		pb->pwm = pwm_request(data->pwm_id, "pwm-backlight");
> > -		if (IS_ERR(pb->pwm)) {
> > -			dev_err(&pdev->dev, "unable to request legacy PWM\n");
> > -			ret = PTR_ERR(pb->pwm);
> > -			goto err_alloc;
> > -		}
> > +	}
> > +
> > +	if (IS_ERR(pb->pwm)) {
> > +		dev_err(&pdev->dev, "unable to request PWM\n");
> > +		ret = PTR_ERR(pb->pwm);
> > +		goto err_alloc;
> >  	}
> >  
> >  	dev_dbg(&pdev->dev, "got pwm for backlight\n");
> 

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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