[Intel-gfx] [PATCH linux-next] drm/i915/display: Remove the useless variable offset and its assignment

[Jani Nikula]

On Wed, 08 Dec 2021, cgel.zte at gmail.com wrote:
> From: luo penghao <luo.penghao at zte.com.cn>
>
> The existence of offset is meaningless, so it should be deleted.
>
> The clang_analyzer complains as follows:
>
> Value stored to 'offset' is never read
>
> Reported-by: Zeal Robot <zealci at zte.com.cn>
> Signed-off-by: luo penghao <luo.penghao at zte.com.cn>

I've said the same things before, and I'll say them again.

Having an unused variable like this could be an indication of a bug
introduced by an earlier change; maybe we should still be using the
variable but no longer do. Please figure out when the variable became
unused and reference the commit so we can tell.

If cgel.zte at gmail.com sends the patches, we'll need their name and
Signed-off-by too.

Thanks for the report, but I'll consider this as a report only.


BR,
Jani.


> ---
>  drivers/gpu/drm/i915/display/i9xx_plane.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/i9xx_plane.c b/drivers/gpu/drm/i915/display/i9xx_plane.c
> index b1439ba..a478b7f 100644
> --- a/drivers/gpu/drm/i915/display/i9xx_plane.c
> +++ b/drivers/gpu/drm/i915/display/i9xx_plane.c
> @@ -964,7 +964,7 @@ i9xx_get_initial_plane_config(struct intel_crtc *crtc,
>  	struct intel_plane *plane = to_intel_plane(crtc->base.primary);
>  	enum i9xx_plane_id i9xx_plane = plane->i9xx_plane;
>  	enum pipe pipe;
> -	u32 val, base, offset;
> +	u32 val, base;
>  	int fourcc, pixel_format;
>  	unsigned int aligned_height;
>  	struct drm_framebuffer *fb;
> @@ -1006,14 +1006,14 @@ i9xx_get_initial_plane_config(struct intel_crtc *crtc,
>  	fb->format = drm_format_info(fourcc);
>  
>  	if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) {
> -		offset = intel_de_read(dev_priv, DSPOFFSET(i9xx_plane));
> +		intel_de_read(dev_priv, DSPOFFSET(i9xx_plane));
>  		base = intel_de_read(dev_priv, DSPSURF(i9xx_plane)) & 0xfffff000;
>  	} else if (DISPLAY_VER(dev_priv) >= 4) {
>  		if (plane_config->tiling)
> -			offset = intel_de_read(dev_priv,
> +			intel_de_read(dev_priv,
>  					       DSPTILEOFF(i9xx_plane));
>  		else
> -			offset = intel_de_read(dev_priv,
> +			intel_de_read(dev_priv,
>  					       DSPLINOFF(i9xx_plane));
>  		base = intel_de_read(dev_priv, DSPSURF(i9xx_plane)) & 0xfffff000;
>  	} else {

-- 
Jani Nikula, Intel Open Source Graphics Center