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

Jingoo Han
2014-07-10T02:29:04Z

On Thursday, July 10, 2014 7:08 AM, Rickard Strandqvist wrote:
> 2014-07-09 18:30 GMT+02:00 Lee Jones <lee.jones@linaro.org>:
> > 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@spectrumdigital.se>
> >> ---
> >> 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@spectrumdigital.se>
> Suggested-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>

I suggest the following.

Suggested-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Cc: Bryan Wu <cooloney@gmail.com>

Best regards,
Jingoo Han

>
>
> Kind regards
> Rickard Strandqvist