Re: [PATCH 2/2] ASoC: codec: wm8960: Relax bit clock computation when using PLL

From: kbuild test robot
Date: Wed Apr 05 2017 - 06:18:39 EST


Hi Daniel,

[auto build test WARNING on asoc/for-next]
[also build test WARNING on next-20170405]
[cannot apply to v4.11-rc5]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url: https://github.com/0day-ci/linux/commits/Daniel-Baluta/ASoC-codec-wm8960-Relax-bit-clock-computation-when-using-PLL/20170405-144647
base: https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next
config: i386-randconfig-s0-201714 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
# save the attached .config to linux build tree
make ARCH=i386

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/codecs/wm8960.c: In function 'wm8960_configure_clocking':
>> sound/soc/codecs/wm8960.c:743:3: warning: 'best_freq_out' may be used uninitialized in this function [-Wmaybe-uninitialized]
wm8960_set_pll(codec, freq_in, best_freq_out);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sound/soc/codecs/wm8960.c:703:21: note: 'best_freq_out' was declared here
int diff, closest, best_freq_out;
^~~~~~~~~~~~~
sound/soc/codecs/wm8960.c:806:56: warning: 'j' may be used uninitialized in this function [-Wmaybe-uninitialized]
snd_soc_update_bits(codec, WM8960_CLOCK1, 0x7 << 6, j << 6);
~~^~~~
sound/soc/codecs/wm8960.c:802:54: warning: 'i' may be used uninitialized in this function [-Wmaybe-uninitialized]
snd_soc_update_bits(codec, WM8960_CLOCK1, 3 << 1, i << 1);
~~^~~~

vim +/best_freq_out +743 sound/soc/codecs/wm8960.c

6b662dee Daniel Baluta 2017-04-04 727 *bclk_idx = k;
6b662dee Daniel Baluta 2017-04-04 728 best_freq_out = freq_out;
6b662dee Daniel Baluta 2017-04-04 729 break;
6b662dee Daniel Baluta 2017-04-04 730 }
16c42f46 Daniel Baluta 2017-04-04 731 if (diff > 0 && closest > diff) {
16c42f46 Daniel Baluta 2017-04-04 732 *sysclk_idx = i;
16c42f46 Daniel Baluta 2017-04-04 733 *dac_idx = j;
16c42f46 Daniel Baluta 2017-04-04 734 *bclk_idx = k;
16c42f46 Daniel Baluta 2017-04-04 735 closest = diff;
16c42f46 Daniel Baluta 2017-04-04 736 best_freq_out = freq_out;
16c42f46 Daniel Baluta 2017-04-04 737 }
6b662dee Daniel Baluta 2017-04-04 738 }
6b662dee Daniel Baluta 2017-04-04 739 }
6b662dee Daniel Baluta 2017-04-04 740 }
6b662dee Daniel Baluta 2017-04-04 741
6b662dee Daniel Baluta 2017-04-04 742 if (*bclk_idx != -1)
6b662dee Daniel Baluta 2017-04-04 @743 wm8960_set_pll(codec, freq_in, best_freq_out);
6b662dee Daniel Baluta 2017-04-04 744
6b662dee Daniel Baluta 2017-04-04 745 return *bclk_idx;
6b662dee Daniel Baluta 2017-04-04 746 }
3176bf2d Zidan Wang 2015-08-11 747 static int wm8960_configure_clocking(struct snd_soc_codec *codec)
0e50b51a Zidan Wang 2015-05-12 748 {
0e50b51a Zidan Wang 2015-05-12 749 struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec);
6b662dee Daniel Baluta 2017-04-04 750 int freq_out, freq_in;
0e50b51a Zidan Wang 2015-05-12 751 u16 iface1 = snd_soc_read(codec, WM8960_IFACE1);

:::::: The code at line 743 was first introduced by commit
:::::: 6b662deec0da0ad4f9dce8112d01828ed72b5a4c ASoC: codec: wm9860: Refactor PLL out freq search

:::::: TO: Daniel Baluta <daniel.baluta@xxxxxxx>
:::::: CC: 0day robot <fengguang.wu@xxxxxxxxx>

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