linux-kernel - drivers/video/fbdev/core/fb_logo.c:67:41-42: WARNING opportunity for min() (fwd)

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Date: Sat, 30 Dec 2023 09:56:00 +0100 (CET)
From: Julia Lawall <julia.lawall@...ia.fr>
To: Thomas Zimmermann <tzimmermann@...e.de>
cc: linux-kernel@...r.kernel.org, oe-kbuild-all@...ts.linux.dev
Subject: drivers/video/fbdev/core/fb_logo.c:67:41-42: WARNING opportunity
 for min() (fwd)



---------- Forwarded message ----------
Date: Sat, 30 Dec 2023 15:22:13 +0800
From: kernel test robot <lkp@...el.com>
To: oe-kbuild@...ts.linux.dev
Cc: lkp@...el.com, Julia Lawall <julia.lawall@...ia.fr>
Subject: drivers/video/fbdev/core/fb_logo.c:67:41-42: WARNING opportunity for
    min()

BCC: lkp@...el.com
CC: oe-kbuild-all@...ts.linux.dev
CC: linux-kernel@...r.kernel.org
TO: Thomas Zimmermann <tzimmermann@...e.de>

Hi Thomas,

FYI, the error/warning was bisected to this commit, please ignore it if it's irrelevant.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   f016f7547aeedefed9450499d002ba983b8fce15
commit: 8887086ef2e0047ec321103a15e7d766be3a3874 fbdev/core: Move logo functions into separate source file
date:   4 months ago
:::::: branch date: 11 hours ago
:::::: commit date: 4 months ago
config: hexagon-randconfig-r052-20231228 (https://download.01.org/0day-ci/archive/20231230/202312301511.93E0cv5e-lkp@intel.com/config)
compiler: clang version 18.0.0git (https://github.com/llvm/llvm-project d3ef86708241a3bee902615c190dead1638c4e09)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@...el.com>
| Reported-by: Julia Lawall <julia.lawall@...ia.fr>
| Closes: https://lore.kernel.org/r/202312301511.93E0cv5e-lkp@intel.com/

cocci warnings: (new ones prefixed by >>)
>> drivers/video/fbdev/core/fb_logo.c:67:41-42: WARNING opportunity for min()
   drivers/video/fbdev/core/fb_logo.c:68:41-42: WARNING opportunity for min()
   drivers/video/fbdev/core/fb_logo.c:69:41-42: WARNING opportunity for min()

vim +67 drivers/video/fbdev/core/fb_logo.c

8887086ef2e004 Thomas Zimmermann 2023-09-07  49
8887086ef2e004 Thomas Zimmermann 2023-09-07  50  static void  fb_set_logo_truepalette(struct fb_info *info,
8887086ef2e004 Thomas Zimmermann 2023-09-07  51  					    const struct linux_logo *logo,
8887086ef2e004 Thomas Zimmermann 2023-09-07  52  					    u32 *palette)
8887086ef2e004 Thomas Zimmermann 2023-09-07  53  {
8887086ef2e004 Thomas Zimmermann 2023-09-07  54  	static const unsigned char mask[] = {
8887086ef2e004 Thomas Zimmermann 2023-09-07  55  		0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff
8887086ef2e004 Thomas Zimmermann 2023-09-07  56  	};
8887086ef2e004 Thomas Zimmermann 2023-09-07  57  	unsigned char redmask, greenmask, bluemask;
8887086ef2e004 Thomas Zimmermann 2023-09-07  58  	int redshift, greenshift, blueshift;
8887086ef2e004 Thomas Zimmermann 2023-09-07  59  	int i;
8887086ef2e004 Thomas Zimmermann 2023-09-07  60  	const unsigned char *clut = logo->clut;
8887086ef2e004 Thomas Zimmermann 2023-09-07  61
8887086ef2e004 Thomas Zimmermann 2023-09-07  62  	/*
8887086ef2e004 Thomas Zimmermann 2023-09-07  63  	 * We have to create a temporary palette since console palette is only
8887086ef2e004 Thomas Zimmermann 2023-09-07  64  	 * 16 colors long.
8887086ef2e004 Thomas Zimmermann 2023-09-07  65  	 */
8887086ef2e004 Thomas Zimmermann 2023-09-07  66  	/* Bug: Doesn't obey msb_right ... (who needs that?) */
8887086ef2e004 Thomas Zimmermann 2023-09-07 @67  	redmask   = mask[info->var.red.length   < 8 ? info->var.red.length   : 8];
8887086ef2e004 Thomas Zimmermann 2023-09-07  68  	greenmask = mask[info->var.green.length < 8 ? info->var.green.length : 8];
8887086ef2e004 Thomas Zimmermann 2023-09-07  69  	bluemask  = mask[info->var.blue.length  < 8 ? info->var.blue.length  : 8];
8887086ef2e004 Thomas Zimmermann 2023-09-07  70  	redshift   = info->var.red.offset   - (8 - info->var.red.length);
8887086ef2e004 Thomas Zimmermann 2023-09-07  71  	greenshift = info->var.green.offset - (8 - info->var.green.length);
8887086ef2e004 Thomas Zimmermann 2023-09-07  72  	blueshift  = info->var.blue.offset  - (8 - info->var.blue.length);
8887086ef2e004 Thomas Zimmermann 2023-09-07  73
8887086ef2e004 Thomas Zimmermann 2023-09-07  74  	for (i = 0; i < logo->clutsize; i++) {
8887086ef2e004 Thomas Zimmermann 2023-09-07  75  		palette[i+32] = (safe_shift((clut[0] & redmask), redshift) |
8887086ef2e004 Thomas Zimmermann 2023-09-07  76  				 safe_shift((clut[1] & greenmask), greenshift) |
8887086ef2e004 Thomas Zimmermann 2023-09-07  77  				 safe_shift((clut[2] & bluemask), blueshift));
8887086ef2e004 Thomas Zimmermann 2023-09-07  78  		clut += 3;
8887086ef2e004 Thomas Zimmermann 2023-09-07  79  	}
8887086ef2e004 Thomas Zimmermann 2023-09-07  80  }
8887086ef2e004 Thomas Zimmermann 2023-09-07  81

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki