Re: [PATCH net-next 8/8] net: mscc: PTP Hardware Clock (PHC) support

From: kbuild test robot <lkp@intel.com>
To: Antoine Tenart <antoine.tenart@bootlin.com>
Cc: kbuild-all@01.org, davem@davemloft.net, richardcochran@gmail.com,
	alexandre.belloni@bootlin.com, UNGLinuxDriver@microchip.com,
	ralf@linux-mips.org, paul.burton@mips.com, jhogan@kernel.org,
	Antoine Tenart <antoine.tenart@bootlin.com>,
	netdev@vger.kernel.org, linux-mips@vger.kernel.org,
	thomas.petazzoni@bootlin.com, allan.nielsen@microchip.com
Subject: Re: [PATCH net-next 8/8] net: mscc: PTP Hardware Clock (PHC) support
Date: Thu, 4 Jul 2019 20:48:10 +0800	[thread overview]
Message-ID: <201907042001.FgaVfD5y%lkp@intel.com> (raw)
In-Reply-To: <20190701100327.6425-9-antoine.tenart@bootlin.com>

[-- Attachment #1: Type: text/plain, Size: 4549 bytes --]

Hi Antoine,

I love your patch! Perhaps something to improve:

[auto build test WARNING on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Antoine-Tenart/net-mscc-PTP-Hardware-Clock-PHC-support/20190702-182042
config: x86_64-randconfig-s2-07041950 (attached as .config)
compiler: gcc-7 (Debian 7.4.0-9) 7.4.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

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 >>):

   In file included from include/linux/irqflags.h:16:0,
                    from arch/x86/include/asm/processor.h:33,
                    from arch/x86/include/asm/cpufeature.h:5,
                    from arch/x86/include/asm/thread_info.h:53,
                    from include/linux/thread_info.h:38,
                    from arch/x86/include/asm/preempt.h:7,
                    from include/linux/preempt.h:78,
                    from include/linux/spinlock.h:51,
                    from include/linux/seqlock.h:36,
                    from include/linux/time.h:6,
                    from include/linux/skbuff.h:15,
                    from include/linux/if_ether.h:19,
                    from include/linux/etherdevice.h:20,
                    from drivers/net/ethernet/mscc/ocelot.c:7:
   drivers/net/ethernet/mscc/ocelot.c: In function 'ocelot_ptp_adjfine':
>> arch/x86/include/asm/irqflags.h:41:2: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized]
     asm volatile("push %0 ; popf"
     ^~~
   drivers/net/ethernet/mscc/ocelot.c:1904:16: note: 'flags' was declared here
     unsigned long flags;
                   ^~~~~
--
   In file included from include/linux/irqflags.h:16:0,
                    from arch/x86/include/asm/processor.h:33,
                    from arch/x86/include/asm/cpufeature.h:5,
                    from arch/x86/include/asm/thread_info.h:53,
                    from include/linux/thread_info.h:38,
                    from arch/x86/include/asm/preempt.h:7,
                    from include/linux/preempt.h:78,
                    from include/linux/spinlock.h:51,
                    from include/linux/seqlock.h:36,
                    from include/linux/time.h:6,
                    from include/linux/skbuff.h:15,
                    from include/linux/if_ether.h:19,
                    from include/linux/etherdevice.h:20,
                    from drivers/net//ethernet/mscc/ocelot.c:7:
   drivers/net//ethernet/mscc/ocelot.c: In function 'ocelot_ptp_adjfine':
>> arch/x86/include/asm/irqflags.h:41:2: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized]
     asm volatile("push %0 ; popf"
     ^~~
   drivers/net//ethernet/mscc/ocelot.c:1904:16: note: 'flags' was declared here
     unsigned long flags;
                   ^~~~~

vim +/flags +41 arch/x86/include/asm/irqflags.h

6abcd98f include/asm-x86/irqflags.h      Glauber de Oliveira Costa 2008-01-30  37  
1f59a458 arch/x86/include/asm/irqflags.h Nick Desaulniers          2018-08-27  38  extern inline void native_restore_fl(unsigned long flags);
1f59a458 arch/x86/include/asm/irqflags.h Nick Desaulniers          2018-08-27  39  extern inline void native_restore_fl(unsigned long flags)
6abcd98f include/asm-x86/irqflags.h      Glauber de Oliveira Costa 2008-01-30  40  {
cf7f7191 include/asm-x86/irqflags.h      Joe Perches               2008-03-23 @41  	asm volatile("push %0 ; popf"
6abcd98f include/asm-x86/irqflags.h      Glauber de Oliveira Costa 2008-01-30  42  		     : /* no output */
6abcd98f include/asm-x86/irqflags.h      Glauber de Oliveira Costa 2008-01-30  43  		     :"g" (flags)
cf7f7191 include/asm-x86/irqflags.h      Joe Perches               2008-03-23  44  		     :"memory", "cc");
6abcd98f include/asm-x86/irqflags.h      Glauber de Oliveira Costa 2008-01-30  45  }
6abcd98f include/asm-x86/irqflags.h      Glauber de Oliveira Costa 2008-01-30  46  

:::::: The code at line 41 was first introduced by commit
:::::: cf7f7191cf20011e47243b594e433275a6db811b include/asm-x86/irqflags.h: checkpatch cleanups - formatting only

:::::: TO: Joe Perches <joe@perches.com>
:::::: CC: Ingo Molnar <mingo@elte.hu>

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

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 38820 bytes --]