[PATCH 11/28] drm/i915/writeback: Define encoder->get_hw_state

[kernel test robot]

Hi Suraj,

kernel test robot noticed the following build errors:

[auto build test ERROR on drm-intel/for-linux-next]
[also build test ERROR on v6.16-rc7 next-20250725]
[cannot apply to linus/master]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Suraj-Kandpal/drm-writeback-Add-function-that-takes-preallocated-connector/20250725-133017
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
patch link:    https://lore.kernel.org/r/20250725050409.2687242-12-suraj.kandpal%40intel.com
patch subject: [PATCH 11/28] drm/i915/writeback: Define encoder->get_hw_state
config: i386-buildonly-randconfig-006-20250725 (https://download.01.org/0day-ci/archive/20250726/202507261936.cnkpq7bw-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250726/202507261936.cnkpq7bw-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 at intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202507261936.cnkpq7bw-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/gpu/drm/i915/display/intel_writeback.c:177:3: error: fallthrough annotation does not directly precede switch label
     177 |                 fallthrough;
         |                 ^
   include/linux/compiler_attributes.h:214:41: note: expanded from macro 'fallthrough'
     214 | # define fallthrough                    __attribute__((__fallthrough__))
         |                                         ^
   1 error generated.


vim +177 drivers/gpu/drm/i915/display/intel_writeback.c

   141	
   142	static bool
   143	intel_writeback_get_hw_state(struct intel_encoder *encoder,
   144				     enum pipe *pipe)
   145	{
   146		struct intel_display *display = to_intel_display(encoder);
   147		u8 pipe_mask = 0;
   148		u32 tmp;
   149	
   150		/* TODO need to be done for both the wd transcoder */
   151		tmp = intel_de_read(display,
   152				    TRANSCONF_WD(TRANSCODER_WD_0));
   153		if (!(tmp & WD_TRANS_ENABLE))
   154			return false;
   155	
   156		tmp = intel_de_read(display,
   157				    WD_TRANS_FUNC_CTL(TRANSCODER_WD_0));
   158	
   159		if (!(tmp & TRANS_WD_FUNC_ENABLE))
   160			return false;
   161	
   162		switch (tmp & WD_INPUT_SELECT_MASK) {
   163		case WD_INPUT_PIPE_A:
   164			pipe_mask |= BIT(PIPE_A);
   165			break;
   166		case WD_INPUT_PIPE_B:
   167			pipe_mask |= BIT(PIPE_B);
   168			break;
   169		case WD_INPUT_PIPE_C:
   170			pipe_mask |= BIT(PIPE_C);
   171			break;
   172		case WD_INPUT_PIPE_D:
   173			pipe_mask |= BIT(PIPE_D);
   174			break;
   175		default:
   176			MISSING_CASE(tmp & WD_INPUT_SELECT_MASK);
 > 177			fallthrough;
   178		}
   179	
   180		if (pipe_mask == 0)
   181			return false;
   182	
   183		*pipe = ffs(pipe_mask) - 1;
   184	
   185		return true;
   186	}
   187	

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