[asahilinux:pr/186 2/2] drivers/gpu/drm/apple/dcp.c:452:17: warning: suggest explicit braces to avoid ambiguous 'else'

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

tree:   https://github.com/AsahiLinux/linux pr/186
head:   c9f888a04befbdc1e8b3b32dbdf41ffeb3f8ecaa
commit: c9f888a04befbdc1e8b3b32dbdf41ffeb3f8ecaa [2/2] drm: apple: Update supported firmware versions to 12.3 and 13.5
config: arm64-allyesconfig (https://download.01.org/0day-ci/archive/20230926/202309260409.ICpXTKXF-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230926/202309260409.ICpXTKXF-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/202309260409.ICpXTKXF-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/gpu/drm/apple/dcp.c: In function 'dcp_crtc_atomic_check':
   drivers/gpu/drm/apple/dcp.c:208:45: warning: variable 'old_state' set but not used [-Wunused-but-set-variable]
     208 |         struct drm_plane_state *new_state, *old_state;
         |                                             ^~~~~~~~~
   drivers/gpu/drm/apple/dcp.c: In function 'dcp_check_firmware_version':
>> drivers/gpu/drm/apple/dcp.c:452:17: warning: suggest explicit braces to avoid ambiguous 'else' [-Wdangling-else]
     452 |         else if (strncmp(compat_str, "13.3.0", sizeof(compat_str)) == 0)
         |                 ^


vim +/else +452 drivers/gpu/drm/apple/dcp.c

   427	
   428	static enum dcp_firmware_version dcp_check_firmware_version(struct device *dev)
   429	{
   430		char compat_str[DCP_FW_VERSION_STR_LEN];
   431		char fw_str[DCP_FW_VERSION_STR_LEN];
   432		int ret;
   433	
   434		/* firmware version is just informative */
   435		dcp_read_fw_version(dev, "apple,firmware-version", fw_str);
   436	
   437		ret = dcp_read_fw_version(dev, "apple,firmware-compat", compat_str);
   438		if (ret < 0) {
   439			dev_err(dev, "Could not read 'apple,firmware-compat': %d\n", ret);
   440			return DCP_FIRMWARE_UNKNOWN;
   441		}
   442	
   443		if (strncmp(compat_str, "12.3.0", sizeof(compat_str)) == 0)
   444			return DCP_FIRMWARE_V_12_3;
   445		/*
   446		 * m1n1 reports firmware version 13.5 as compatible with 13.3. This is
   447		 * only true for the iomfb endpoint. The interface for the dptx-port
   448		 * endpoint changed between 13.3 and 13.5. The driver will only support
   449		 * firmware 13.5. Check the actual firmware version for compat version
   450		 * 13.3 until m1n1 reports 13.5 as "firmware-compat".
   451		 */
 > 452		else if (strncmp(compat_str, "13.3.0", sizeof(compat_str)) == 0)
   453			if (strncmp(fw_str, "13.5.0", sizeof(compat_str)) == 0)
   454				return DCP_FIRMWARE_V_13_5;
   455		else if (strncmp(compat_str, "13.5.0", sizeof(compat_str)) == 0)
   456			return DCP_FIRMWARE_V_13_5;
   457	
   458		dev_err(dev, "DCP firmware-compat %s (FW: %s) is not supported\n",
   459			compat_str, fw_str);
   460	
   461		return DCP_FIRMWARE_UNKNOWN;
   462	}
   463	

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