Re: [PATCH v2 2/2] drm/bridge: Add ITE IT6162 MIPI DSI to HDMI bridge driver

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

Hi Hermes,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 2622649ad6cdbb3e77bfafc8c0fe686090b77f70]

url:    https://github.com/intel-lab-lkp/linux/commits/Hermes-Wu-via-B4-Relay/dt-bindings-display-bridge-Add-ITE-IT6162-MIPI-DSI-to-HDMI-bridge/20260309-174457
base:   2622649ad6cdbb3e77bfafc8c0fe686090b77f70
patch link:    https://lore.kernel.org/r/20260309-upstream-6162-v2-2-debdb6c88030%40ite.com.tw
patch subject: [PATCH v2 2/2] drm/bridge: Add ITE IT6162 MIPI DSI to HDMI bridge driver
config: hexagon-allmodconfig (https://download.01.org/0day-ci/archive/20260309/202603092305.W1fFHKL5-lkp@intel.com/config)
compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260309/202603092305.W1fFHKL5-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/202603092305.W1fFHKL5-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/bridge/ite-it6162.c:728:7: warning: variable 'cp_status' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
     728 |                 if (it6162->hdcp_sts != hdcp_sts ||
         |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     729 |                     it6162->hdcp_sts == NO_HDCP_STATE) {
         |                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/gpu/drm/bridge/ite-it6162.c:759:57: note: uninitialized use occurs here
     759 |                 drm_hdcp_update_content_protection(it6162->connector, cp_status);
         |                                                                       ^~~~~~~~~
   drivers/gpu/drm/bridge/ite-it6162.c:728:3: note: remove the 'if' if its condition is always true
     728 |                 if (it6162->hdcp_sts != hdcp_sts ||
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     729 |                     it6162->hdcp_sts == NO_HDCP_STATE) {
         |                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/gpu/drm/bridge/ite-it6162.c:703:15: note: initialize the variable 'cp_status' to silence this warning
     703 |         u64 cp_status;
         |                      ^
         |                       = 0
   1 warning generated.


vim +728 drivers/gpu/drm/bridge/ite-it6162.c

   695	
   696	static void it6162_hdcp_handler(struct it6162 *it6162)
   697	{
   698		struct regmap *regmap = it6162->regmap;
   699		unsigned int tx_status, sink_cap;
   700		enum hdcp_state hdcp_sts;
   701		struct it6162_hdcp_cfg *hdcp_cfg = &it6162->hdcp_cfg;
   702		u8 hdcp_ver;
   703		u64 cp_status;
   704	
   705		if (hdcp_cfg->hdcp_version == NO_HDCP || !it6162->en_hdcp) {
   706			drm_dbg(it6162->drm, "HDCP not enabled, skip hdcp check");
   707			return;
   708		}
   709	
   710		regmap_read(regmap, OFFSET_TX_STATUS, &tx_status);
   711		regmap_read(regmap, OFFSET_SINK_CAP, &sink_cap);
   712	
   713		drm_dbg(it6162->drm, "Tx status %x", tx_status);
   714		drm_dbg(it6162->drm, "SINK capability %x", sink_cap);
   715	
   716		if (!GET_TX_VIDEO_STATUS(tx_status)) {
   717			drm_dbg(it6162->drm, "video not stable, skip hdcp check");
   718			return;
   719		}
   720	
   721		hdcp_sts = GET_TX_HDCP_STATUS(tx_status);
   722		hdcp_ver = GET_SINK_CAP_HDCP_VER(sink_cap);
   723		drm_dbg(it6162->drm, "hdcp status: %x->%x, version: %x-%x",
   724			it6162->hdcp_sts, hdcp_sts,
   725			it6162->hdcp_version, hdcp_ver);
   726	
   727		if (it6162->hdcp_version != NO_HDCP) {
 > 728			if (it6162->hdcp_sts != hdcp_sts ||
   729			    it6162->hdcp_sts == NO_HDCP_STATE) {
   730				it6162->hdcp_sts = hdcp_sts;
   731				cp_status = DRM_MODE_CONTENT_PROTECTION_DESIRED;
   732				switch (hdcp_sts) {
   733				case AUTH_DONE:
   734					drm_dbg(it6162->drm, "HDCP AUTH DONE");
   735					it6162_update_hdcp(it6162);
   736					cp_status = DRM_MODE_CONTENT_PROTECTION_ENABLED;
   737					break;
   738				case AUTH_FAIL:
   739					drm_dbg(it6162->drm, "HDCP AUTH FAIL");
   740					if (hdcp_ver == HDCP_23) {
   741						drm_dbg(it6162->drm,
   742							"HDCP 2.3 auth fail, change to HDCP 1.4");
   743						it6162_tx_hdcp_setup(it6162,
   744								     HDCP_14,
   745								     true);
   746					} else {
   747						it6162_tx_hdcp_disable(it6162);
   748					}
   749	
   750					break;
   751				default:
   752					drm_dbg(it6162->drm, "HDCP NO AUTH");
   753					it6162_tx_hdcp_setup(it6162,
   754							     it6162->hdcp_version,
   755							     true);
   756					break;
   757				}
   758			}
   759			drm_hdcp_update_content_protection(it6162->connector, cp_status);
   760		}
   761	}
   762	

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