linux-kernel - Re: [PATCH] backlight: pwm_bl: Don't assign levels table repeatedly

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Message-ID: <20191002163248.GE87296@google.com>
Date:   Wed, 2 Oct 2019 09:32:48 -0700
From:   Matthias Kaehlcke <mka@...omium.org>
To:     Daniel Thompson <daniel.thompson@...aro.org>
Cc:     Thierry Reding <thierry.reding@...il.com>,
        Lee Jones <lee.jones@...aro.org>,
        Jingoo Han <jingoohan1@...il.com>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        linux-pwm@...r.kernel.org, linux-fbdev@...r.kernel.org,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] backlight: pwm_bl: Don't assign levels table repeatedly

On Wed, Oct 02, 2019 at 11:07:37AM +0100, Daniel Thompson wrote:
> On Tue, Oct 01, 2019 at 04:29:24PM -0700, Matthias Kaehlcke wrote:
> > pwm_backlight_probe() re-assigns pb->levels for every brightness
> > level. This is not needed and was likely not intended, since
> > neither side of the assignment changes during the loop. Assign
> > the field only once.
> > 
> > Signed-off-by: Matthias Kaehlcke <mka@...omium.org>
> 
> Makes sense but this should probably be dropping the curly braces too.

ack, I'll send a new version with the curly braces removed.

> >  drivers/video/backlight/pwm_bl.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> > index 746eebc411df..959436b9e92b 100644
> > --- a/drivers/video/backlight/pwm_bl.c
> > +++ b/drivers/video/backlight/pwm_bl.c
> > @@ -564,6 +564,8 @@ static int pwm_backlight_probe(struct platform_device *pdev)
> >  	memset(&props, 0, sizeof(struct backlight_properties));
> >  
> >  	if (data->levels) {
> > +		pb->levels = data->levels;
> > +
> >  		/*
> >  		 * For the DT case, only when brightness levels is defined
> >  		 * data->levels is filled. For the non-DT case, data->levels
> > @@ -572,8 +574,6 @@ static int pwm_backlight_probe(struct platform_device *pdev)
> >  		for (i = 0; i <= data->max_brightness; i++) {
> >  			if (data->levels[i] > pb->scale)
> >  				pb->scale = data->levels[i];
> > -
> > -			pb->levels = data->levels;
> >  		}
> >  
> >  		if (pwm_backlight_is_linear(data))
> > -- 
> > 2.23.0.444.g18eeb5a265-goog
> >