Re: [Intel-gfx] [PATCH v5 3/6] drm/i915/panelreplay: Initializaton and compute config for panel replay

[kernel test robot <lkp@intel.com>]

Hi Animesh,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-tip/drm-tip]

url:    https://github.com/intel-lab-lkp/linux/commits/Animesh-Manna/drm-panelreplay-dpcd-register-definition-for-panelreplay/20230905-154811
base:   git://anongit.freedesktop.org/drm/drm-tip drm-tip
patch link:    https://lore.kernel.org/r/20230905073551.958368-4-animesh.manna%40intel.com
patch subject: [Intel-gfx] [PATCH v5 3/6] drm/i915/panelreplay: Initializaton and compute config for panel replay
config: i386-randconfig-r036-20230905 (https://download.01.org/0day-ci/archive/20230905/202309051831.AMUjJOcB-lkp@intel.com/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230905/202309051831.AMUjJOcB-lkp@intel.com/reproduce)

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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202309051831.AMUjJOcB-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/i915/display/intel_dp.c:3779:27: warning: overlapping comparisons always evaluate to true [-Wtautological-overlap-compare]
           if (vsc->revision != 0x5 || vsc->revision != 0x7)
               ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
   1 warning generated.


vim +3779 drivers/gpu/drm/i915/display/intel_dp.c

  3754	
  3755	static ssize_t intel_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc,
  3756					     struct dp_sdp *sdp, size_t size)
  3757	{
  3758		size_t length = sizeof(struct dp_sdp);
  3759	
  3760		if (size < length)
  3761			return -ENOSPC;
  3762	
  3763		memset(sdp, 0, size);
  3764	
  3765		/*
  3766		 * Prepare VSC Header for SU as per DP 1.4a spec, Table 2-119
  3767		 * VSC SDP Header Bytes
  3768		 */
  3769		sdp->sdp_header.HB0 = 0; /* Secondary-Data Packet ID = 0 */
  3770		sdp->sdp_header.HB1 = vsc->sdp_type; /* Secondary-data Packet Type */
  3771		sdp->sdp_header.HB2 = vsc->revision; /* Revision Number */
  3772		sdp->sdp_header.HB3 = vsc->length; /* Number of Valid Data Bytes */
  3773	
  3774		/*
  3775		 * Other than revision 0x5 which supports Pixel Encoding/Colorimetry
  3776		 * Format as per DP 1.4a spec, revision 0x7 also supports Pixel
  3777		 * Encoding/Colorimetry Format as per DP 2.0 spec.
  3778		 */
> 3779		if (vsc->revision != 0x5 || vsc->revision != 0x7)
  3780			goto out;
  3781	
  3782		/* VSC SDP Payload for DB16 through DB18 */
  3783		/* Pixel Encoding and Colorimetry Formats  */
  3784		sdp->db[16] = (vsc->pixelformat & 0xf) << 4; /* DB16[7:4] */
  3785		sdp->db[16] |= vsc->colorimetry & 0xf; /* DB16[3:0] */
  3786	
  3787		switch (vsc->bpc) {
  3788		case 6:
  3789			/* 6bpc: 0x0 */
  3790			break;
  3791		case 8:
  3792			sdp->db[17] = 0x1; /* DB17[3:0] */
  3793			break;
  3794		case 10:
  3795			sdp->db[17] = 0x2;
  3796			break;
  3797		case 12:
  3798			sdp->db[17] = 0x3;
  3799			break;
  3800		case 16:
  3801			sdp->db[17] = 0x4;
  3802			break;
  3803		default:
  3804			MISSING_CASE(vsc->bpc);
  3805			break;
  3806		}
  3807		/* Dynamic Range and Component Bit Depth */
  3808		if (vsc->dynamic_range == DP_DYNAMIC_RANGE_CTA)
  3809			sdp->db[17] |= 0x80;  /* DB17[7] */
  3810	
  3811		/* Content Type */
  3812		sdp->db[18] = vsc->content_type & 0x7;
  3813	
  3814	out:
  3815		return length;
  3816	}
  3817	

-- 
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https://github.com/intel/lkp-tests/wiki