linux-kernel - Re: [PATCH 1/2] fbdev: Move two variable assignments in fb_alloc_cmap

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Message-ID: <35bb7db7-bf14-20ba-3bff-80d05c42e28b@gmx.de>
Date:   Wed, 24 May 2023 20:10:55 +0200
From:   Helge Deller <deller@....de>
To:     Markus Elfring <Markus.Elfring@....de>,
        kernel-janitors@...r.kernel.org, linux-fbdev@...r.kernel.org,
        dri-devel@...ts.freedesktop.org, Daniel Vetter <daniel@...ll.ch>
Cc:     LKML <linux-kernel@...r.kernel.org>, cocci@...ia.fr
Subject: Re: [PATCH 1/2] fbdev: Move two variable assignments in
 fb_alloc_cmap_gfp()

On 5/23/23 22:15, Markus Elfring wrote:
> From: Markus Elfring <elfring@...rs.sourceforge.net>
> Date: Tue, 23 May 2023 21:30:29 +0200
>
> Move the assignment for the local variables “size” and “flags”
> because the computed values were only used in a single if branch.

Please do not move such variables without real need.
It makes backporting (of this and maybe follow-up patches) much more
complicated and the compiler will optimize it anyway.

Thanks!
Helge


> Signed-off-by: Markus Elfring <elfring@...rs.sourceforge.net>
> ---
>   drivers/video/fbdev/core/fbcmap.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/video/fbdev/core/fbcmap.c b/drivers/video/fbdev/core/fbcmap.c
> index ff09e57f3c38..5c1075ed28ab 100644
> --- a/drivers/video/fbdev/core/fbcmap.c
> +++ b/drivers/video/fbdev/core/fbcmap.c
> @@ -91,16 +91,17 @@ static const struct fb_cmap default_16_colors = {
>
>   int fb_alloc_cmap_gfp(struct fb_cmap *cmap, int len, int transp, gfp_t flags)
>   {
> -	int size = len * sizeof(u16);
>   	int ret = -ENOMEM;
>
> -	flags |= __GFP_NOWARN;
> -
>   	if (cmap->len != len) {
> +		int size;
> +
>   		fb_dealloc_cmap(cmap);
>   		if (!len)
>   			return 0;
>
> +		size = len * sizeof(u16);
> +		flags |= __GFP_NOWARN;
>   		cmap->red = kzalloc(size, flags);
>   		if (!cmap->red)
>   			goto fail;
> --
> 2.40.1
>