Re: [PATCH] ath9k: feeding entropy in kernel from ADC capture

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

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Hi Miaoqing,

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

config: tile-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 220286596260e48c3c25675309d3c7d4f0875198
  # save the attached .config to linux build tree
  make.cross ARCH=tile 

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 >>):

   drivers/net/wireless/ath/ath9k/rng.c: In function 'ath9k_rng_data_read.constprop.0':
>> drivers/net/wireless/ath/ath9k/rng.c:53:15: warning: 'v2' may be used uninitialized in this function [-Wuninitialized]

vim +/v2 +53 drivers/net/wireless/ath/ath9k/rng.c

    37		REG_RMW_FIELD(ah, AR_PHY_TEST_CTL_STATUS, AR_PHY_TEST_CTL_RX_OBS_SEL, 0);
    38	
    39		for (i = 0, j = 0; i < buf_size; i++) {
    40			v1 = REG_READ(ah, AR_PHY_TST_ADC) & 0xffff;
    41			v2 = REG_READ(ah, AR_PHY_TST_ADC) & 0xffff;
    42	
    43			/* wait for data ready */
    44			if (v1 && v2 && rng_last != v1 && v1 != v2 && v1 != 0xffff &&
    45			    v2 != 0xffff)
    46				buf[j++] = (v1 << 16) | v2;
    47	
    48			rng_last = v2;
    49		}
    50	
    51		ath9k_ps_restore(sc);
    52	
  > 53		sc->rng_last = v2;
    54	
    55		return j << 2;
    56	}
    57	
    58	static int ath9k_rng_kthread(void *data)
    59	{
    60		int bytes_read;
    61		struct ath_softc *sc = data;

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

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