Re: [PATCH] video: backlight: jornada720_lcd.c: Cleaning up variable that is never used

[Jingoo Han]

On Thursday, July 10, 2014 7:08 AM, Rickard Strandqvist wrote:
> 2014-07-09 18:30 GMT+02:00 Lee Jones <lee.jones@xxxxxxxxxx>:
> > On Mon, 07 Jul 2014, Rickard Strandqvist wrote:
> >
> >> Variable ar assigned a value that is never used.
> >> I have also removed all the code that thereby serves no purpose,
> >> and made same change to clarify the similarities in function.
> >>
> >> This was found using a static code analysis program called cppcheck
> >>
> >> Signed-off-by: Rickard Strandqvist <rickard_strandqvist@xxxxxxxxxxxxxxxxxx>
> >> ---
> >>  drivers/video/backlight/jornada720_lcd.c |   31 ++++++++++++++----------------
> >>  1 file changed, 14 insertions(+), 17 deletions(-)
> >>
> >> diff --git a/drivers/video/backlight/jornada720_lcd.c b/drivers/video/backlight/jornada720_lcd.c
> >> index da3876c..d16abcf 100644
> >> --- a/drivers/video/backlight/jornada720_lcd.c
> >> +++ b/drivers/video/backlight/jornada720_lcd.c
> >> @@ -36,44 +36,41 @@ static int jornada_lcd_get_power(struct lcd_device *ld)
> >>
> >>  static int jornada_lcd_get_contrast(struct lcd_device *ld)
> >>  {
> >> -     int ret;
> >> +     int ret = -ETIMEDOUT;
> >>
> >>       if (jornada_lcd_get_power(ld) != FB_BLANK_UNBLANK)
> >>               return 0;
> >>
> >>       jornada_ssp_start();
> >>
> >> -     if (jornada_ssp_byte(GETCONTRAST) != TXDUMMY) {
> >> +     if (jornada_ssp_byte(GETCONTRAST) != TXDUMMY)
> >>               dev_err(&ld->dev, "get contrast failed\n");
> >> -             jornada_ssp_end();
> >> -             return -ETIMEDOUT;
> >> -     } else {
> >> +     else
> >>               ret = jornada_ssp_byte(TXDUMMY);
> >> -             jornada_ssp_end();
> >> -             return ret;
> >> -     }
> >> +
> >> +     jornada_ssp_end();
> >> +
> >> +     return ret;
> >>  }
> >>
> >>  static int jornada_lcd_set_contrast(struct lcd_device *ld, int value)
> >>  {
> >> -     int ret;
> >> +     int ret = -ETIMEDOUT;
> >>
> >>       jornada_ssp_start();
> >>
> >>       /* start by sending our set contrast cmd to mcu */
> >> -     ret = jornada_ssp_byte(SETCONTRAST);
> >> -
> >> +     if (jornada_ssp_byte(SETCONTRAST) != TXDUMMY)
> >> +             dev_err(&ld->dev, "set contrast failed\n");
> >>       /* push the new value */
> >> -     if (jornada_ssp_byte(value) != TXDUMMY) {
> >> +     else if (jornada_ssp_byte(value) != TXDUMMY)
> >>               dev_err(&ld->dev, "set contrast failed\n");
> >> -             jornada_ssp_end();
> >> -             return -ETIMEDOUT;
> >> -     }
> >> +     else /* if we get here we can assume everything went well */
> >> +             ret = 0;
> >>
> >> -     /* if we get here we can assume everything went well */
> >>       jornada_ssp_end();
> >>
> >> -     return 0;
> >> +     return ret;
> >>  }
> >>
> >>  static int jornada_lcd_set_power(struct lcd_device *ld, int power)
> >
> > Counter suggestion.
> >
> > What do you think, I think this looks cleaner:
> >
> > static int jornada_lcd_get_contrast(struct lcd_device *ld)
> > {
> >         int ret;
> >
> >         if (jornada_lcd_get_power(ld) != FB_BLANK_UNBLANK)
> >                 return 0;
> >
> >         jornada_ssp_start();
> >
> >         if (jornada_ssp_byte(GETCONTRAST) == TXDUMMY) {
> >                 ret = jornada_ssp_byte(TXDUMMY);
> >                 goto success;
> >         }
> >
> >         dev_err(&ld->dev, "failed to set contrast\n");
> >         ret = -ETIMEDOUT;
> >
> > success:
> >         jornada_ssp_end();
> >         return ret;
> > }
> >
> > static int jornada_lcd_set_contrast(struct lcd_device *ld, int value)
> > {
> >         int ret = 0;
> >
> >         jornada_ssp_start();
> >
> >         /* start by sending our set contrast cmd to mcu */
> >         if (jornada_ssp_byte(SETCONTRAST) == TXDUMMY) {
> >                 /* if successful, push the new value */
> >                 if (jornada_ssp_byte(value) == TXDUMMY)
> >                         goto success;
> >         }
> >
> >         dev_err(&ld->dev, "failed to set contrast\n");
> >         ret = -ETIMEDOUT;
> >
> > success:
> >         jornada_ssp_end();
> >         return ret;
> > }
> 
> 
> Hi Lee!
> 
> Yes, I agree!
> Both are clean without so much repetition of code, which was what annoyd me.
> But yours is clearer when things go good or bad, nice 1 ;)

Hi Rickard Strandqvist,

I would liked to prefer Lee Jones's code. It looks cleaner.

> 
> I do not know what I can/may do, but I'll try. Remove what is not ok :-)
> 
> Reviewed-by: Rickard Strandqvist <rickard_strandqvist@xxxxxxxxxxxxxxxxxx>
> Suggested-by: Rickard Strandqvist <rickard_strandqvist@xxxxxxxxxxxxxxxxxx>

I suggest the following.

Suggested-by: Rickard Strandqvist <rickard_strandqvist@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
Acked-by: Jingoo Han <jg1.han@xxxxxxxxxxx>
Cc: Bryan Wu <cooloney@xxxxxxxxx>

Best regards,
Jingoo Han

> 
> 
> Kind regards
> Rickard Strandqvist

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