Re: [PATCH RFC] video: fbdev: sis: condition with no effect

From: Scot Doyle
Date: Thu Feb 05 2015 - 15:48:19 EST


On Wed, 4 Feb 2015, Nicholas Mc Guire wrote:
> The if and the else branch code are identical - so the condition has no
> effect on the effective code - this patch removes the condition and the
> duplicated code.
>
> Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>
> ---
>
> This code has been in here since commit 544393fe584d ("sisfb update") so I guess it is
> safe to simply remove the duplicated code if nobody noticed for 10 years.
>
> Note that the code is not really CodingStyle compliant - the lines inserted were formatted
> to satisfy the coding style but I'm unsure if it is not better to leave it in the
> old format.
>
> Patch was only compile tested with x86_64_defconfig +
> CONFIG_FB_SIS=m, CONFIG_FB_SIS_300=y, CONFIG_FB_SIS_315=y
>
> Patch is against 3.19.0-rc7 (localversion-next is -next-20150204)
>
> drivers/video/fbdev/sis/init301.c | 9 ++-------
> 1 file changed, 2 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/video/fbdev/sis/init301.c b/drivers/video/fbdev/sis/init301.c
> index 295e0de..9533a8ab 100644
> --- a/drivers/video/fbdev/sis/init301.c
> +++ b/drivers/video/fbdev/sis/init301.c
> @@ -7971,13 +7971,8 @@ SiS_SetCHTVReg(struct SiS_Private *SiS_Pr, unsigned short ModeNo, unsigned short
> }
> } else { /* ---- PAL ---- */
> /* We don't play around with FSCI in PAL mode */
> - if(resindex == 0x04) {
> - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */
> - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */
> - } else {
> - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */
> - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */
> - }
> + SiS_SetCH70xxANDOR(SiS_Pr, 0x20, 0x00, 0xEF); /* loop filter off */
> + SiS_SetCH70xxANDOR(SiS_Pr, 0x21, 0x01, 0xFE); /* ACIV on */
> }
>
> #endif /* 300 */

The code covering the PAL case had this redundancy when it was introduced
in Linux 2.4.19.

Lines 7934-7981 consider three variables: PAL, overscan, and resindex.
Given the "#ifdef 0" block, couldn't the current six sections collapse
into two? One for (!PAL && overscan && resindex==5) and another for the
rest?
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