Re: [PATCH] extcon: Allow registering a single notifier for all cables on an extcon_dev

[kbuild test robot]

Hi Hans,

[auto build test WARNING on chanwoo-extcon/extcon-next]
[also build test WARNING on v4.11-rc2 next-20170310]
[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/Hans-de-Goede/extcon-Allow-registering-a-single-notifier-for-all-cables-on-an-extcon_dev/20170319-204610
base:   https://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/extcon.git extcon-next
config: i386-randconfig-x072-201712 (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 >>):

   drivers/extcon/extcon.c: In function 'extcon_unregister_notifier':
>> drivers/extcon/extcon.c:962:48: warning: 'idx' may be used uninitialized in this function [-Wmaybe-uninitialized]
      ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
                                                   ^

vim +/idx +962 drivers/extcon/extcon.c

74c5d09b drivers/extcon/extcon_class.c Donggeun Kim  2012-04-20  946  				struct notifier_block *nb)
74c5d09b drivers/extcon/extcon_class.c Donggeun Kim  2012-04-20  947  {
66bee35f drivers/extcon/extcon.c       Hans de Goede 2015-03-21  948  	unsigned long flags;
046050f6 drivers/extcon/extcon.c       Chanwoo Choi  2015-05-19  949  	int ret, idx;
046050f6 drivers/extcon/extcon.c       Chanwoo Choi  2015-05-19  950  
7eae43ae drivers/extcon/extcon.c       Chanwoo Choi  2015-06-21  951  	if (!edev || !nb)
7eae43ae drivers/extcon/extcon.c       Chanwoo Choi  2015-06-21  952  		return -EINVAL;
7eae43ae drivers/extcon/extcon.c       Chanwoo Choi  2015-06-21  953  
8f482488 drivers/extcon/extcon.c       Hans de Goede 2017-03-17  954  	if ((int)id != -1) {
046050f6 drivers/extcon/extcon.c       Chanwoo Choi  2015-05-19  955  		idx = find_cable_index_by_id(edev, id);
a05f44c8 drivers/extcon/extcon.c       Stephen Boyd  2016-06-23  956  		if (idx < 0)
a05f44c8 drivers/extcon/extcon.c       Stephen Boyd  2016-06-23  957  			return idx;
8f482488 drivers/extcon/extcon.c       Hans de Goede 2017-03-17  958  	}
66bee35f drivers/extcon/extcon.c       Hans de Goede 2015-03-21  959  
66bee35f drivers/extcon/extcon.c       Hans de Goede 2015-03-21  960  	spin_lock_irqsave(&edev->lock, flags);
8f482488 drivers/extcon/extcon.c       Hans de Goede 2017-03-17  961  	if ((int)id != -1)
046050f6 drivers/extcon/extcon.c       Chanwoo Choi  2015-05-19 @962  		ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
8f482488 drivers/extcon/extcon.c       Hans de Goede 2017-03-17  963  	else
8f482488 drivers/extcon/extcon.c       Hans de Goede 2017-03-17  964  		ret = raw_notifier_chain_unregister(&edev->nh_all, nb);
8f482488 drivers/extcon/extcon.c       Hans de Goede 2017-03-17  965  
66bee35f drivers/extcon/extcon.c       Hans de Goede 2015-03-21  966  	spin_unlock_irqrestore(&edev->lock, flags);
66bee35f drivers/extcon/extcon.c       Hans de Goede 2015-03-21  967  
66bee35f drivers/extcon/extcon.c       Hans de Goede 2015-03-21  968  	return ret;
74c5d09b drivers/extcon/extcon_class.c Donggeun Kim  2012-04-20  969  }
74c5d09b drivers/extcon/extcon_class.c Donggeun Kim  2012-04-20  970  EXPORT_SYMBOL_GPL(extcon_unregister_notifier);

:::::: The code at line 962 was first introduced by commit
:::::: 046050f6e623e442e9c71c525462ebd395dae526 extcon: Update the prototype of extcon_register_notifier() with enum extcon

:::::: TO: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
:::::: CC: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>

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