Hi Damien.Horsley,

[auto build test results on v4.3-rc3 -- if it's inappropriate base, please ignore]

config: sh-allyesconfig (attached as .config)
reproduce:
  wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
  chmod +x ~/bin/make.cross
  git checkout 5037c15dd47c86ab337b73c7f9ffcabe1bb86f3b
  # save the attached .config to linux build tree
  make.cross ARCH=sh 

Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings

All warnings (new ones prefixed by >>):

   sound/soc/img/img-i2s-out.c: In function 'img_i2s_out_set_fmt':

quoted

sound/soc/img/img-i2s-out.c:108:2: warning: 'reg' may be used uninitialized in this function [-Wuninitialized]

   sound/soc/img/img-i2s-out.c:291:6: note: 'reg' was declared here

vim +/reg +108 sound/soc/img/img-i2s-out.c

    92	}
    93	
    94	static inline void img_i2s_out_writel(struct img_i2s_out *i2s, u32 val,
    95						u32 reg)
    96	{
    97		writel(val, i2s->base + reg);
    98	}
    99	
   100	static inline u32 img_i2s_out_readl(struct img_i2s_out *i2s, u32 reg)
   101	{
   102		return readl(i2s->base + reg);
   103	}
   104	
   105	static inline void img_i2s_out_ch_writel(struct img_i2s_out *i2s,
   106						u32 chan, u32 val, u32 reg)
   107	{
 > 108		writel(val, i2s->channel_base + (chan * IMG_I2S_OUT_CH_STRIDE) + reg);
   109	}
   110	
   111	static inline u32 img_i2s_out_ch_readl(struct img_i2s_out *i2s, u32 chan,
   112						u32 reg)
   113	{
   114		return readl(i2s->channel_base + (chan * IMG_I2S_OUT_CH_STRIDE) + reg);
   115	}
   116	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation