All of lore.kernel.org
 help / color / mirror / Atom feed
From: kbuild test robot <lkp@intel.com>
To: changbin.du@intel.com
Cc: kbuild-all@01.org, mingo@redhat.com, akpm@linux-foundation.org,
	yamada.masahiro@socionext.com, michal.lkml@markovi.net,
	rostedt@goodmis.org, tglx@linutronix.de, rdunlap@infradead.org,
	x86@kernel.org, linux@armlinux.org.uk, lgirdwood@gmail.com,
	broonie@kernel.org, arnd@arndb.de, linux-kbuild@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-sparse@vger.kernel.org, changbin.du@gmail.com,
	Changbin Du <changbin.du@intel.com>
Subject: Re: [PATCH v5 4/4] kernel hacking: new config CC_OPTIMIZE_FOR_DEBUGGING to apply GCC -Og optimization
Date: Sun, 10 Jun 2018 23:49:55 +0800	[thread overview]
Message-ID: <201806101929.E2oiistg%fengguang.wu@intel.com> (raw)
In-Reply-To: <1528186420-6615-5-git-send-email-changbin.du@intel.com>

[-- Attachment #1: Type: text/plain, Size: 15903 bytes --]

Hi Changbin,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v4.17 next-20180608]
[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/changbin-du-intel-com/kernel-hacking-GCC-optimization-for-better-debug-experience-Og/20180606-001415
config: i386-randconfig-x076-06101602 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
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//usb/typec/fusb302/fusb302.c: In function 'fusb302_handle_togdone_src':
>> drivers//usb/typec/fusb302/fusb302.c:1413:10: warning: 'ra_comp' may be used uninitialized in this function [-Wmaybe-uninitialized]
     else if (ra_comp)
             ^
--
   drivers/infiniband/ulp/ipoib/ipoib_main.c: In function 'ipoib_get_netdev':
>> drivers/infiniband/ulp/ipoib/ipoib_main.c:2021:30: warning: 'dev' may be used uninitialized in this function [-Wmaybe-uninitialized]
     if (!hca->alloc_rdma_netdev || PTR_ERR(dev) == -EOPNOTSUPP)
--
   kernel//cgroup/cgroup-v1.c: In function 'cgroup1_mount':
>> kernel//cgroup/cgroup-v1.c:1268:3: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized]
      percpu_ref_reinit(&root->cgrp.self.refcnt);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   kernel//trace/bpf_trace.c: In function 'bpf_trace_printk':
>> kernel//trace/bpf_trace.c:226:20: warning: 'unsafe_addr' may be used uninitialized in this function [-Wmaybe-uninitialized]
              (void *) (long) unsafe_addr,
                       ^~~~~~~~~~~~~~~~~~
   kernel//trace/bpf_trace.c:170:6: note: 'unsafe_addr' was declared here
     u64 unsafe_addr;
         ^~~~~~~~~~~
--
   net//6lowpan/iphc.c: In function 'lowpan_header_decompress':
   net//6lowpan/iphc.c:617:12: warning: 'iphc1' may be used uninitialized in this function [-Wmaybe-uninitialized]
     u8 iphc0, iphc1, cid = 0;
               ^~~~~
>> net//6lowpan/iphc.c:617:5: warning: 'iphc0' may be used uninitialized in this function [-Wmaybe-uninitialized]
     u8 iphc0, iphc1, cid = 0;
        ^~~~~
--
   net//netfilter/nf_tables_api.c: In function 'nf_tables_dump_set':
>> net//netfilter/nf_tables_api.c:3625:2: warning: 'set' may be used uninitialized in this function [-Wmaybe-uninitialized]
     set->ops->walk(&dump_ctx->ctx, set, &args.iter);
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   drivers/media/dvb-frontends/mn88472.c: In function 'mn88472_set_frontend':
>> drivers/media/dvb-frontends/mn88472.c:339:27: warning: 'bandwidth_vals_ptr' may be used uninitialized in this function [-Wmaybe-uninitialized]
            bandwidth_vals_ptr[i]);
                              ^
>> drivers/media/dvb-frontends/mn88472.c:320:8: warning: 'bandwidth_val' may be used uninitialized in this function [-Wmaybe-uninitialized]
     ret = regmap_write(dev->regmap[2], 0x04, bandwidth_val);
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   drivers/media/dvb-frontends/mn88473.c: In function 'mn88473_set_frontend':
>> drivers/media/dvb-frontends/mn88473.c:162:7: warning: 'conf_val_ptr' may be used uninitialized in this function [-Wmaybe-uninitialized]
      ret = regmap_bulk_write(dev->regmap[1], 0x10, conf_val_ptr, 6);
      ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   net//netfilter/ipvs/ip_vs_sync.c: In function 'ip_vs_sync_conn':
>> net//netfilter/ipvs/ip_vs_sync.c:731:13: warning: 'm' may be used uninitialized in this function [-Wmaybe-uninitialized]
     m->nr_conns++;
     ~~~~~~~~~~~^~
--
   drivers//hwspinlock/hwspinlock_core.c: In function 'of_hwspin_lock_get_id':
>> drivers//hwspinlock/hwspinlock_core.c:339:19: warning: 'id' may be used uninitialized in this function [-Wmaybe-uninitialized]
     return ret ? ret : id;
            ~~~~~~~~~~^~~~
--
   drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c: In function 'mlxsw_sp_nexthop_group_update':
>> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3078:7: warning: 'err' may be used uninitialized in this function [-Wmaybe-uninitialized]
       if (err)
          ^

vim +/ra_comp +1413 drivers//usb/typec/fusb302/fusb302.c

c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1359  
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1360  static int fusb302_handle_togdone_src(struct fusb302_chip *chip,
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1361  				      u8 togdone_result)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1362  {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1363  	/*
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1364  	 * - set polarity (measure cc, vconn, tx)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1365  	 * - set pull_up, pull_down
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1366  	 * - set cc1, cc2, and update to tcpm_port
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1367  	 * - set I_COMP interrupt on
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1368  	 */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1369  	int ret = 0;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1370  	u8 status0;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1371  	u8 ra_mda = ra_mda_value[chip->src_current_status];
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1372  	u8 rd_mda = rd_mda_value[chip->src_current_status];
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1373  	bool ra_comp, rd_comp;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1374  	enum typec_cc_polarity cc_polarity;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1375  	enum typec_cc_status cc_status_active, cc1, cc2;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1376  
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1377  	/* set pull_up, pull_down */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1378  	ret = fusb302_set_cc_pull(chip, true, false);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1379  	if (ret < 0) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1380  		fusb302_log(chip, "cannot set cc to pull up, ret=%d", ret);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1381  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1382  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1383  	/* set polarity */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1384  	cc_polarity = (togdone_result == FUSB_REG_STATUS1A_TOGSS_SRC1) ?
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1385  		      TYPEC_POLARITY_CC1 : TYPEC_POLARITY_CC2;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1386  	ret = fusb302_set_cc_polarity(chip, cc_polarity);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1387  	if (ret < 0) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1388  		fusb302_log(chip, "cannot set cc polarity %s, ret=%d",
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1389  			    cc_polarity_name[cc_polarity], ret);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1390  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1391  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1392  	/* fusb302_set_cc_polarity() has set the correct measure block */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1393  	ret = fusb302_i2c_write(chip, FUSB_REG_MEASURE, rd_mda);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1394  	if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1395  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1396  	usleep_range(50, 100);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1397  	ret = fusb302_i2c_read(chip, FUSB_REG_STATUS0, &status0);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1398  	if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1399  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1400  	rd_comp = !!(status0 & FUSB_REG_STATUS0_COMP);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1401  	if (!rd_comp) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1402  		ret = fusb302_i2c_write(chip, FUSB_REG_MEASURE, ra_mda);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1403  		if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1404  			return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1405  		usleep_range(50, 100);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1406  		ret = fusb302_i2c_read(chip, FUSB_REG_STATUS0, &status0);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1407  		if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1408  			return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1409  		ra_comp = !!(status0 & FUSB_REG_STATUS0_COMP);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1410  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1411  	if (rd_comp)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1412  		cc_status_active = TYPEC_CC_OPEN;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27 @1413  	else if (ra_comp)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1414  		cc_status_active = TYPEC_CC_RD;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1415  	else
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1416  		/* Ra is not supported, report as Open */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1417  		cc_status_active = TYPEC_CC_OPEN;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1418  	/* restart toggling if the cc status on the active line is OPEN */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1419  	if (cc_status_active == TYPEC_CC_OPEN) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1420  		fusb302_log(chip, "restart toggling as CC_OPEN detected");
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1421  		ret = fusb302_set_toggling(chip, chip->toggling_mode);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1422  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1423  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1424  	/* update tcpm with the new cc value */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1425  	cc1 = (cc_polarity == TYPEC_POLARITY_CC1) ?
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1426  	      cc_status_active : TYPEC_CC_OPEN;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1427  	cc2 = (cc_polarity == TYPEC_POLARITY_CC2) ?
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1428  	      cc_status_active : TYPEC_CC_OPEN;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1429  	if ((chip->cc1 != cc1) || (chip->cc2 != cc2)) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1430  		chip->cc1 = cc1;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1431  		chip->cc2 = cc2;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1432  		tcpm_cc_change(chip->tcpm_port);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1433  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1434  	/* turn off toggling */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1435  	ret = fusb302_set_toggling(chip, TOGGLINE_MODE_OFF);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1436  	if (ret < 0) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1437  		fusb302_log(chip,
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1438  			    "cannot set toggling mode off, ret=%d", ret);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1439  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1440  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1441  	/* set MDAC to Rd threshold, and unmask I_COMP for unplug detection */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1442  	ret = fusb302_i2c_write(chip, FUSB_REG_MEASURE, rd_mda);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1443  	if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1444  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1445  	/* unmask comp_chng interrupt */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1446  	ret = fusb302_i2c_clear_bits(chip, FUSB_REG_MASK,
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1447  				     FUSB_REG_MASK_COMP_CHNG);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1448  	if (ret < 0) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1449  		fusb302_log(chip,
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1450  			    "cannot unmask bc_lcl interrupt, ret=%d", ret);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1451  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1452  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1453  	chip->intr_comp_chng = true;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1454  	fusb302_log(chip, "detected cc1=%s, cc2=%s",
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1455  		    typec_cc_status_name[cc1],
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1456  		    typec_cc_status_name[cc2]);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1457  
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1458  	return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1459  }
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1460  

:::::: The code at line 1413 was first introduced by commit
:::::: c034a43e72dda58e4a184d71f5502ef356e04453 staging: typec: Fairchild FUSB302 Type-c chip driver

:::::: TO: Yueyao Zhu <yueyao@google.com>
:::::: CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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: 30857 bytes --]

WARNING: multiple messages have this Message-ID (diff)
From: kbuild test robot <lkp@intel.com>
Cc: kbuild-all@01.org, mingo@redhat.com, akpm@linux-foundation.org,
	yamada.masahiro@socionext.com, michal.lkml@markovi.net,
	rostedt@goodmis.org, tglx@linutronix.de, rdunlap@infradead.org,
	x86@kernel.org, linux@armlinux.org.uk, lgirdwood@gmail.com,
	broonie@kernel.org, arnd@arndb.de, linux-kbuild@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-sparse@vger.kernel.org, changbin.du@gmail.com,
	Changbin Du <changbin.du@intel.com>
Subject: Re: [PATCH v5 4/4] kernel hacking: new config CC_OPTIMIZE_FOR_DEBUGGING to apply GCC -Og optimization
Date: Sun, 10 Jun 2018 23:49:55 +0800	[thread overview]
Message-ID: <201806101929.E2oiistg%fengguang.wu@intel.com> (raw)
In-Reply-To: <1528186420-6615-5-git-send-email-changbin.du@intel.com>

[-- Attachment #1: Type: text/plain, Size: 15903 bytes --]

Hi Changbin,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v4.17 next-20180608]
[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/changbin-du-intel-com/kernel-hacking-GCC-optimization-for-better-debug-experience-Og/20180606-001415
config: i386-randconfig-x076-06101602 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
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//usb/typec/fusb302/fusb302.c: In function 'fusb302_handle_togdone_src':
>> drivers//usb/typec/fusb302/fusb302.c:1413:10: warning: 'ra_comp' may be used uninitialized in this function [-Wmaybe-uninitialized]
     else if (ra_comp)
             ^
--
   drivers/infiniband/ulp/ipoib/ipoib_main.c: In function 'ipoib_get_netdev':
>> drivers/infiniband/ulp/ipoib/ipoib_main.c:2021:30: warning: 'dev' may be used uninitialized in this function [-Wmaybe-uninitialized]
     if (!hca->alloc_rdma_netdev || PTR_ERR(dev) == -EOPNOTSUPP)
--
   kernel//cgroup/cgroup-v1.c: In function 'cgroup1_mount':
>> kernel//cgroup/cgroup-v1.c:1268:3: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized]
      percpu_ref_reinit(&root->cgrp.self.refcnt);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   kernel//trace/bpf_trace.c: In function 'bpf_trace_printk':
>> kernel//trace/bpf_trace.c:226:20: warning: 'unsafe_addr' may be used uninitialized in this function [-Wmaybe-uninitialized]
              (void *) (long) unsafe_addr,
                       ^~~~~~~~~~~~~~~~~~
   kernel//trace/bpf_trace.c:170:6: note: 'unsafe_addr' was declared here
     u64 unsafe_addr;
         ^~~~~~~~~~~
--
   net//6lowpan/iphc.c: In function 'lowpan_header_decompress':
   net//6lowpan/iphc.c:617:12: warning: 'iphc1' may be used uninitialized in this function [-Wmaybe-uninitialized]
     u8 iphc0, iphc1, cid = 0;
               ^~~~~
>> net//6lowpan/iphc.c:617:5: warning: 'iphc0' may be used uninitialized in this function [-Wmaybe-uninitialized]
     u8 iphc0, iphc1, cid = 0;
        ^~~~~
--
   net//netfilter/nf_tables_api.c: In function 'nf_tables_dump_set':
>> net//netfilter/nf_tables_api.c:3625:2: warning: 'set' may be used uninitialized in this function [-Wmaybe-uninitialized]
     set->ops->walk(&dump_ctx->ctx, set, &args.iter);
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   drivers/media/dvb-frontends/mn88472.c: In function 'mn88472_set_frontend':
>> drivers/media/dvb-frontends/mn88472.c:339:27: warning: 'bandwidth_vals_ptr' may be used uninitialized in this function [-Wmaybe-uninitialized]
            bandwidth_vals_ptr[i]);
                              ^
>> drivers/media/dvb-frontends/mn88472.c:320:8: warning: 'bandwidth_val' may be used uninitialized in this function [-Wmaybe-uninitialized]
     ret = regmap_write(dev->regmap[2], 0x04, bandwidth_val);
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   drivers/media/dvb-frontends/mn88473.c: In function 'mn88473_set_frontend':
>> drivers/media/dvb-frontends/mn88473.c:162:7: warning: 'conf_val_ptr' may be used uninitialized in this function [-Wmaybe-uninitialized]
      ret = regmap_bulk_write(dev->regmap[1], 0x10, conf_val_ptr, 6);
      ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   net//netfilter/ipvs/ip_vs_sync.c: In function 'ip_vs_sync_conn':
>> net//netfilter/ipvs/ip_vs_sync.c:731:13: warning: 'm' may be used uninitialized in this function [-Wmaybe-uninitialized]
     m->nr_conns++;
     ~~~~~~~~~~~^~
--
   drivers//hwspinlock/hwspinlock_core.c: In function 'of_hwspin_lock_get_id':
>> drivers//hwspinlock/hwspinlock_core.c:339:19: warning: 'id' may be used uninitialized in this function [-Wmaybe-uninitialized]
     return ret ? ret : id;
            ~~~~~~~~~~^~~~
--
   drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c: In function 'mlxsw_sp_nexthop_group_update':
>> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3078:7: warning: 'err' may be used uninitialized in this function [-Wmaybe-uninitialized]
       if (err)
          ^

vim +/ra_comp +1413 drivers//usb/typec/fusb302/fusb302.c

c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1359  
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1360  static int fusb302_handle_togdone_src(struct fusb302_chip *chip,
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1361  				      u8 togdone_result)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1362  {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1363  	/*
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1364  	 * - set polarity (measure cc, vconn, tx)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1365  	 * - set pull_up, pull_down
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1366  	 * - set cc1, cc2, and update to tcpm_port
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1367  	 * - set I_COMP interrupt on
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1368  	 */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1369  	int ret = 0;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1370  	u8 status0;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1371  	u8 ra_mda = ra_mda_value[chip->src_current_status];
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1372  	u8 rd_mda = rd_mda_value[chip->src_current_status];
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1373  	bool ra_comp, rd_comp;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1374  	enum typec_cc_polarity cc_polarity;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1375  	enum typec_cc_status cc_status_active, cc1, cc2;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1376  
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1377  	/* set pull_up, pull_down */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1378  	ret = fusb302_set_cc_pull(chip, true, false);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1379  	if (ret < 0) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1380  		fusb302_log(chip, "cannot set cc to pull up, ret=%d", ret);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1381  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1382  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1383  	/* set polarity */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1384  	cc_polarity = (togdone_result == FUSB_REG_STATUS1A_TOGSS_SRC1) ?
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1385  		      TYPEC_POLARITY_CC1 : TYPEC_POLARITY_CC2;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1386  	ret = fusb302_set_cc_polarity(chip, cc_polarity);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1387  	if (ret < 0) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1388  		fusb302_log(chip, "cannot set cc polarity %s, ret=%d",
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1389  			    cc_polarity_name[cc_polarity], ret);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1390  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1391  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1392  	/* fusb302_set_cc_polarity() has set the correct measure block */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1393  	ret = fusb302_i2c_write(chip, FUSB_REG_MEASURE, rd_mda);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1394  	if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1395  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1396  	usleep_range(50, 100);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1397  	ret = fusb302_i2c_read(chip, FUSB_REG_STATUS0, &status0);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1398  	if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1399  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1400  	rd_comp = !!(status0 & FUSB_REG_STATUS0_COMP);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1401  	if (!rd_comp) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1402  		ret = fusb302_i2c_write(chip, FUSB_REG_MEASURE, ra_mda);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1403  		if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1404  			return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1405  		usleep_range(50, 100);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1406  		ret = fusb302_i2c_read(chip, FUSB_REG_STATUS0, &status0);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1407  		if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1408  			return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1409  		ra_comp = !!(status0 & FUSB_REG_STATUS0_COMP);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1410  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1411  	if (rd_comp)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1412  		cc_status_active = TYPEC_CC_OPEN;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27 @1413  	else if (ra_comp)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1414  		cc_status_active = TYPEC_CC_RD;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1415  	else
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1416  		/* Ra is not supported, report as Open */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1417  		cc_status_active = TYPEC_CC_OPEN;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1418  	/* restart toggling if the cc status on the active line is OPEN */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1419  	if (cc_status_active == TYPEC_CC_OPEN) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1420  		fusb302_log(chip, "restart toggling as CC_OPEN detected");
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1421  		ret = fusb302_set_toggling(chip, chip->toggling_mode);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1422  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1423  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1424  	/* update tcpm with the new cc value */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1425  	cc1 = (cc_polarity == TYPEC_POLARITY_CC1) ?
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1426  	      cc_status_active : TYPEC_CC_OPEN;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1427  	cc2 = (cc_polarity == TYPEC_POLARITY_CC2) ?
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1428  	      cc_status_active : TYPEC_CC_OPEN;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1429  	if ((chip->cc1 != cc1) || (chip->cc2 != cc2)) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1430  		chip->cc1 = cc1;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1431  		chip->cc2 = cc2;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1432  		tcpm_cc_change(chip->tcpm_port);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1433  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1434  	/* turn off toggling */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1435  	ret = fusb302_set_toggling(chip, TOGGLINE_MODE_OFF);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1436  	if (ret < 0) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1437  		fusb302_log(chip,
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1438  			    "cannot set toggling mode off, ret=%d", ret);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1439  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1440  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1441  	/* set MDAC to Rd threshold, and unmask I_COMP for unplug detection */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1442  	ret = fusb302_i2c_write(chip, FUSB_REG_MEASURE, rd_mda);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1443  	if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1444  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1445  	/* unmask comp_chng interrupt */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1446  	ret = fusb302_i2c_clear_bits(chip, FUSB_REG_MASK,
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1447  				     FUSB_REG_MASK_COMP_CHNG);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1448  	if (ret < 0) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1449  		fusb302_log(chip,
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1450  			    "cannot unmask bc_lcl interrupt, ret=%d", ret);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1451  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1452  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1453  	chip->intr_comp_chng = true;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1454  	fusb302_log(chip, "detected cc1=%s, cc2=%s",
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1455  		    typec_cc_status_name[cc1],
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1456  		    typec_cc_status_name[cc2]);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1457  
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1458  	return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1459  }
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1460  

:::::: The code at line 1413 was first introduced by commit
:::::: c034a43e72dda58e4a184d71f5502ef356e04453 staging: typec: Fairchild FUSB302 Type-c chip driver

:::::: TO: Yueyao Zhu <yueyao@google.com>
:::::: CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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: 30857 bytes --]

WARNING: multiple messages have this Message-ID (diff)
From: kbuild test robot <lkp@intel.com>
To: changbin.du@intel.com
Cc: kbuild-all@01.org, mingo@redhat.com, akpm@linux-foundation.org,
	yamada.masahiro@socionext.com, michal.lkml@markovi.net,
	rostedt@goodmis.org, tglx@linutronix.de, rdunlap@infradead.org,
	x86@kernel.org, linux@armlinux.org.uk, lgirdwood@gmail.com,
	broonie@kernel.org, arnd@arndb.de, linux-kbuild@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-sparse@vger.kernel.org, changbin.du@gmail.com
Subject: Re: [PATCH v5 4/4] kernel hacking: new config CC_OPTIMIZE_FOR_DEBUGGING to apply GCC -Og optimization
Date: Sun, 10 Jun 2018 23:49:55 +0800	[thread overview]
Message-ID: <201806101929.E2oiistg%fengguang.wu@intel.com> (raw)
In-Reply-To: <1528186420-6615-5-git-send-email-changbin.du@intel.com>

[-- Attachment #1: Type: text/plain, Size: 15903 bytes --]

Hi Changbin,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v4.17 next-20180608]
[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/changbin-du-intel-com/kernel-hacking-GCC-optimization-for-better-debug-experience-Og/20180606-001415
config: i386-randconfig-x076-06101602 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
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//usb/typec/fusb302/fusb302.c: In function 'fusb302_handle_togdone_src':
>> drivers//usb/typec/fusb302/fusb302.c:1413:10: warning: 'ra_comp' may be used uninitialized in this function [-Wmaybe-uninitialized]
     else if (ra_comp)
             ^
--
   drivers/infiniband/ulp/ipoib/ipoib_main.c: In function 'ipoib_get_netdev':
>> drivers/infiniband/ulp/ipoib/ipoib_main.c:2021:30: warning: 'dev' may be used uninitialized in this function [-Wmaybe-uninitialized]
     if (!hca->alloc_rdma_netdev || PTR_ERR(dev) == -EOPNOTSUPP)
--
   kernel//cgroup/cgroup-v1.c: In function 'cgroup1_mount':
>> kernel//cgroup/cgroup-v1.c:1268:3: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized]
      percpu_ref_reinit(&root->cgrp.self.refcnt);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   kernel//trace/bpf_trace.c: In function 'bpf_trace_printk':
>> kernel//trace/bpf_trace.c:226:20: warning: 'unsafe_addr' may be used uninitialized in this function [-Wmaybe-uninitialized]
              (void *) (long) unsafe_addr,
                       ^~~~~~~~~~~~~~~~~~
   kernel//trace/bpf_trace.c:170:6: note: 'unsafe_addr' was declared here
     u64 unsafe_addr;
         ^~~~~~~~~~~
--
   net//6lowpan/iphc.c: In function 'lowpan_header_decompress':
   net//6lowpan/iphc.c:617:12: warning: 'iphc1' may be used uninitialized in this function [-Wmaybe-uninitialized]
     u8 iphc0, iphc1, cid = 0;
               ^~~~~
>> net//6lowpan/iphc.c:617:5: warning: 'iphc0' may be used uninitialized in this function [-Wmaybe-uninitialized]
     u8 iphc0, iphc1, cid = 0;
        ^~~~~
--
   net//netfilter/nf_tables_api.c: In function 'nf_tables_dump_set':
>> net//netfilter/nf_tables_api.c:3625:2: warning: 'set' may be used uninitialized in this function [-Wmaybe-uninitialized]
     set->ops->walk(&dump_ctx->ctx, set, &args.iter);
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   drivers/media/dvb-frontends/mn88472.c: In function 'mn88472_set_frontend':
>> drivers/media/dvb-frontends/mn88472.c:339:27: warning: 'bandwidth_vals_ptr' may be used uninitialized in this function [-Wmaybe-uninitialized]
            bandwidth_vals_ptr[i]);
                              ^
>> drivers/media/dvb-frontends/mn88472.c:320:8: warning: 'bandwidth_val' may be used uninitialized in this function [-Wmaybe-uninitialized]
     ret = regmap_write(dev->regmap[2], 0x04, bandwidth_val);
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   drivers/media/dvb-frontends/mn88473.c: In function 'mn88473_set_frontend':
>> drivers/media/dvb-frontends/mn88473.c:162:7: warning: 'conf_val_ptr' may be used uninitialized in this function [-Wmaybe-uninitialized]
      ret = regmap_bulk_write(dev->regmap[1], 0x10, conf_val_ptr, 6);
      ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   net//netfilter/ipvs/ip_vs_sync.c: In function 'ip_vs_sync_conn':
>> net//netfilter/ipvs/ip_vs_sync.c:731:13: warning: 'm' may be used uninitialized in this function [-Wmaybe-uninitialized]
     m->nr_conns++;
     ~~~~~~~~~~~^~
--
   drivers//hwspinlock/hwspinlock_core.c: In function 'of_hwspin_lock_get_id':
>> drivers//hwspinlock/hwspinlock_core.c:339:19: warning: 'id' may be used uninitialized in this function [-Wmaybe-uninitialized]
     return ret ? ret : id;
            ~~~~~~~~~~^~~~
--
   drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c: In function 'mlxsw_sp_nexthop_group_update':
>> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3078:7: warning: 'err' may be used uninitialized in this function [-Wmaybe-uninitialized]
       if (err)
          ^

vim +/ra_comp +1413 drivers//usb/typec/fusb302/fusb302.c

c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1359  
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1360  static int fusb302_handle_togdone_src(struct fusb302_chip *chip,
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1361  				      u8 togdone_result)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1362  {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1363  	/*
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1364  	 * - set polarity (measure cc, vconn, tx)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1365  	 * - set pull_up, pull_down
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1366  	 * - set cc1, cc2, and update to tcpm_port
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1367  	 * - set I_COMP interrupt on
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1368  	 */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1369  	int ret = 0;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1370  	u8 status0;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1371  	u8 ra_mda = ra_mda_value[chip->src_current_status];
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1372  	u8 rd_mda = rd_mda_value[chip->src_current_status];
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1373  	bool ra_comp, rd_comp;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1374  	enum typec_cc_polarity cc_polarity;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1375  	enum typec_cc_status cc_status_active, cc1, cc2;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1376  
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1377  	/* set pull_up, pull_down */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1378  	ret = fusb302_set_cc_pull(chip, true, false);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1379  	if (ret < 0) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1380  		fusb302_log(chip, "cannot set cc to pull up, ret=%d", ret);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1381  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1382  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1383  	/* set polarity */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1384  	cc_polarity = (togdone_result == FUSB_REG_STATUS1A_TOGSS_SRC1) ?
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1385  		      TYPEC_POLARITY_CC1 : TYPEC_POLARITY_CC2;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1386  	ret = fusb302_set_cc_polarity(chip, cc_polarity);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1387  	if (ret < 0) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1388  		fusb302_log(chip, "cannot set cc polarity %s, ret=%d",
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1389  			    cc_polarity_name[cc_polarity], ret);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1390  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1391  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1392  	/* fusb302_set_cc_polarity() has set the correct measure block */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1393  	ret = fusb302_i2c_write(chip, FUSB_REG_MEASURE, rd_mda);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1394  	if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1395  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1396  	usleep_range(50, 100);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1397  	ret = fusb302_i2c_read(chip, FUSB_REG_STATUS0, &status0);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1398  	if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1399  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1400  	rd_comp = !!(status0 & FUSB_REG_STATUS0_COMP);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1401  	if (!rd_comp) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1402  		ret = fusb302_i2c_write(chip, FUSB_REG_MEASURE, ra_mda);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1403  		if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1404  			return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1405  		usleep_range(50, 100);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1406  		ret = fusb302_i2c_read(chip, FUSB_REG_STATUS0, &status0);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1407  		if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1408  			return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1409  		ra_comp = !!(status0 & FUSB_REG_STATUS0_COMP);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1410  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1411  	if (rd_comp)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1412  		cc_status_active = TYPEC_CC_OPEN;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27 @1413  	else if (ra_comp)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1414  		cc_status_active = TYPEC_CC_RD;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1415  	else
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1416  		/* Ra is not supported, report as Open */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1417  		cc_status_active = TYPEC_CC_OPEN;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1418  	/* restart toggling if the cc status on the active line is OPEN */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1419  	if (cc_status_active == TYPEC_CC_OPEN) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1420  		fusb302_log(chip, "restart toggling as CC_OPEN detected");
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1421  		ret = fusb302_set_toggling(chip, chip->toggling_mode);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1422  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1423  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1424  	/* update tcpm with the new cc value */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1425  	cc1 = (cc_polarity == TYPEC_POLARITY_CC1) ?
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1426  	      cc_status_active : TYPEC_CC_OPEN;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1427  	cc2 = (cc_polarity == TYPEC_POLARITY_CC2) ?
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1428  	      cc_status_active : TYPEC_CC_OPEN;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1429  	if ((chip->cc1 != cc1) || (chip->cc2 != cc2)) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1430  		chip->cc1 = cc1;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1431  		chip->cc2 = cc2;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1432  		tcpm_cc_change(chip->tcpm_port);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1433  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1434  	/* turn off toggling */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1435  	ret = fusb302_set_toggling(chip, TOGGLINE_MODE_OFF);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1436  	if (ret < 0) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1437  		fusb302_log(chip,
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1438  			    "cannot set toggling mode off, ret=%d", ret);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1439  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1440  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1441  	/* set MDAC to Rd threshold, and unmask I_COMP for unplug detection */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1442  	ret = fusb302_i2c_write(chip, FUSB_REG_MEASURE, rd_mda);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1443  	if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1444  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1445  	/* unmask comp_chng interrupt */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1446  	ret = fusb302_i2c_clear_bits(chip, FUSB_REG_MASK,
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1447  				     FUSB_REG_MASK_COMP_CHNG);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1448  	if (ret < 0) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1449  		fusb302_log(chip,
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1450  			    "cannot unmask bc_lcl interrupt, ret=%d", ret);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1451  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1452  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1453  	chip->intr_comp_chng = true;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1454  	fusb302_log(chip, "detected cc1=%s, cc2=%s",
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1455  		    typec_cc_status_name[cc1],
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1456  		    typec_cc_status_name[cc2]);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1457  
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1458  	return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1459  }
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1460  

:::::: The code at line 1413 was first introduced by commit
:::::: c034a43e72dda58e4a184d71f5502ef356e04453 staging: typec: Fairchild FUSB302 Type-c chip driver

:::::: TO: Yueyao Zhu <yueyao@google.com>
:::::: CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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: 30857 bytes --]

WARNING: multiple messages have this Message-ID (diff)
From: lkp@intel.com (kbuild test robot)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v5 4/4] kernel hacking: new config CC_OPTIMIZE_FOR_DEBUGGING to apply GCC -Og optimization
Date: Sun, 10 Jun 2018 23:49:55 +0800	[thread overview]
Message-ID: <201806101929.E2oiistg%fengguang.wu@intel.com> (raw)
In-Reply-To: <1528186420-6615-5-git-send-email-changbin.du@intel.com>

Hi Changbin,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v4.17 next-20180608]
[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/changbin-du-intel-com/kernel-hacking-GCC-optimization-for-better-debug-experience-Og/20180606-001415
config: i386-randconfig-x076-06101602 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
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//usb/typec/fusb302/fusb302.c: In function 'fusb302_handle_togdone_src':
>> drivers//usb/typec/fusb302/fusb302.c:1413:10: warning: 'ra_comp' may be used uninitialized in this function [-Wmaybe-uninitialized]
     else if (ra_comp)
             ^
--
   drivers/infiniband/ulp/ipoib/ipoib_main.c: In function 'ipoib_get_netdev':
>> drivers/infiniband/ulp/ipoib/ipoib_main.c:2021:30: warning: 'dev' may be used uninitialized in this function [-Wmaybe-uninitialized]
     if (!hca->alloc_rdma_netdev || PTR_ERR(dev) == -EOPNOTSUPP)
--
   kernel//cgroup/cgroup-v1.c: In function 'cgroup1_mount':
>> kernel//cgroup/cgroup-v1.c:1268:3: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized]
      percpu_ref_reinit(&root->cgrp.self.refcnt);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   kernel//trace/bpf_trace.c: In function 'bpf_trace_printk':
>> kernel//trace/bpf_trace.c:226:20: warning: 'unsafe_addr' may be used uninitialized in this function [-Wmaybe-uninitialized]
              (void *) (long) unsafe_addr,
                       ^~~~~~~~~~~~~~~~~~
   kernel//trace/bpf_trace.c:170:6: note: 'unsafe_addr' was declared here
     u64 unsafe_addr;
         ^~~~~~~~~~~
--
   net//6lowpan/iphc.c: In function 'lowpan_header_decompress':
   net//6lowpan/iphc.c:617:12: warning: 'iphc1' may be used uninitialized in this function [-Wmaybe-uninitialized]
     u8 iphc0, iphc1, cid = 0;
               ^~~~~
>> net//6lowpan/iphc.c:617:5: warning: 'iphc0' may be used uninitialized in this function [-Wmaybe-uninitialized]
     u8 iphc0, iphc1, cid = 0;
        ^~~~~
--
   net//netfilter/nf_tables_api.c: In function 'nf_tables_dump_set':
>> net//netfilter/nf_tables_api.c:3625:2: warning: 'set' may be used uninitialized in this function [-Wmaybe-uninitialized]
     set->ops->walk(&dump_ctx->ctx, set, &args.iter);
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   drivers/media/dvb-frontends/mn88472.c: In function 'mn88472_set_frontend':
>> drivers/media/dvb-frontends/mn88472.c:339:27: warning: 'bandwidth_vals_ptr' may be used uninitialized in this function [-Wmaybe-uninitialized]
            bandwidth_vals_ptr[i]);
                              ^
>> drivers/media/dvb-frontends/mn88472.c:320:8: warning: 'bandwidth_val' may be used uninitialized in this function [-Wmaybe-uninitialized]
     ret = regmap_write(dev->regmap[2], 0x04, bandwidth_val);
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   drivers/media/dvb-frontends/mn88473.c: In function 'mn88473_set_frontend':
>> drivers/media/dvb-frontends/mn88473.c:162:7: warning: 'conf_val_ptr' may be used uninitialized in this function [-Wmaybe-uninitialized]
      ret = regmap_bulk_write(dev->regmap[1], 0x10, conf_val_ptr, 6);
      ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   net//netfilter/ipvs/ip_vs_sync.c: In function 'ip_vs_sync_conn':
>> net//netfilter/ipvs/ip_vs_sync.c:731:13: warning: 'm' may be used uninitialized in this function [-Wmaybe-uninitialized]
     m->nr_conns++;
     ~~~~~~~~~~~^~
--
   drivers//hwspinlock/hwspinlock_core.c: In function 'of_hwspin_lock_get_id':
>> drivers//hwspinlock/hwspinlock_core.c:339:19: warning: 'id' may be used uninitialized in this function [-Wmaybe-uninitialized]
     return ret ? ret : id;
            ~~~~~~~~~~^~~~
--
   drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c: In function 'mlxsw_sp_nexthop_group_update':
>> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3078:7: warning: 'err' may be used uninitialized in this function [-Wmaybe-uninitialized]
       if (err)
          ^

vim +/ra_comp +1413 drivers//usb/typec/fusb302/fusb302.c

c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1359  
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1360  static int fusb302_handle_togdone_src(struct fusb302_chip *chip,
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1361  				      u8 togdone_result)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1362  {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1363  	/*
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1364  	 * - set polarity (measure cc, vconn, tx)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1365  	 * - set pull_up, pull_down
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1366  	 * - set cc1, cc2, and update to tcpm_port
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1367  	 * - set I_COMP interrupt on
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1368  	 */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1369  	int ret = 0;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1370  	u8 status0;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1371  	u8 ra_mda = ra_mda_value[chip->src_current_status];
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1372  	u8 rd_mda = rd_mda_value[chip->src_current_status];
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1373  	bool ra_comp, rd_comp;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1374  	enum typec_cc_polarity cc_polarity;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1375  	enum typec_cc_status cc_status_active, cc1, cc2;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1376  
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1377  	/* set pull_up, pull_down */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1378  	ret = fusb302_set_cc_pull(chip, true, false);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1379  	if (ret < 0) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1380  		fusb302_log(chip, "cannot set cc to pull up, ret=%d", ret);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1381  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1382  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1383  	/* set polarity */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1384  	cc_polarity = (togdone_result == FUSB_REG_STATUS1A_TOGSS_SRC1) ?
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1385  		      TYPEC_POLARITY_CC1 : TYPEC_POLARITY_CC2;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1386  	ret = fusb302_set_cc_polarity(chip, cc_polarity);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1387  	if (ret < 0) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1388  		fusb302_log(chip, "cannot set cc polarity %s, ret=%d",
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1389  			    cc_polarity_name[cc_polarity], ret);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1390  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1391  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1392  	/* fusb302_set_cc_polarity() has set the correct measure block */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1393  	ret = fusb302_i2c_write(chip, FUSB_REG_MEASURE, rd_mda);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1394  	if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1395  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1396  	usleep_range(50, 100);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1397  	ret = fusb302_i2c_read(chip, FUSB_REG_STATUS0, &status0);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1398  	if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1399  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1400  	rd_comp = !!(status0 & FUSB_REG_STATUS0_COMP);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1401  	if (!rd_comp) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1402  		ret = fusb302_i2c_write(chip, FUSB_REG_MEASURE, ra_mda);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1403  		if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1404  			return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1405  		usleep_range(50, 100);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1406  		ret = fusb302_i2c_read(chip, FUSB_REG_STATUS0, &status0);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1407  		if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1408  			return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1409  		ra_comp = !!(status0 & FUSB_REG_STATUS0_COMP);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1410  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1411  	if (rd_comp)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1412  		cc_status_active = TYPEC_CC_OPEN;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27 @1413  	else if (ra_comp)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1414  		cc_status_active = TYPEC_CC_RD;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1415  	else
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1416  		/* Ra is not supported, report as Open */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1417  		cc_status_active = TYPEC_CC_OPEN;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1418  	/* restart toggling if the cc status on the active line is OPEN */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1419  	if (cc_status_active == TYPEC_CC_OPEN) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1420  		fusb302_log(chip, "restart toggling as CC_OPEN detected");
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1421  		ret = fusb302_set_toggling(chip, chip->toggling_mode);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1422  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1423  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1424  	/* update tcpm with the new cc value */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1425  	cc1 = (cc_polarity == TYPEC_POLARITY_CC1) ?
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1426  	      cc_status_active : TYPEC_CC_OPEN;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1427  	cc2 = (cc_polarity == TYPEC_POLARITY_CC2) ?
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1428  	      cc_status_active : TYPEC_CC_OPEN;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1429  	if ((chip->cc1 != cc1) || (chip->cc2 != cc2)) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1430  		chip->cc1 = cc1;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1431  		chip->cc2 = cc2;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1432  		tcpm_cc_change(chip->tcpm_port);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1433  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1434  	/* turn off toggling */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1435  	ret = fusb302_set_toggling(chip, TOGGLINE_MODE_OFF);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1436  	if (ret < 0) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1437  		fusb302_log(chip,
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1438  			    "cannot set toggling mode off, ret=%d", ret);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1439  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1440  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1441  	/* set MDAC to Rd threshold, and unmask I_COMP for unplug detection */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1442  	ret = fusb302_i2c_write(chip, FUSB_REG_MEASURE, rd_mda);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1443  	if (ret < 0)
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1444  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1445  	/* unmask comp_chng interrupt */
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1446  	ret = fusb302_i2c_clear_bits(chip, FUSB_REG_MASK,
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1447  				     FUSB_REG_MASK_COMP_CHNG);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1448  	if (ret < 0) {
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1449  		fusb302_log(chip,
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1450  			    "cannot unmask bc_lcl interrupt, ret=%d", ret);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1451  		return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1452  	}
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1453  	chip->intr_comp_chng = true;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1454  	fusb302_log(chip, "detected cc1=%s, cc2=%s",
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1455  		    typec_cc_status_name[cc1],
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1456  		    typec_cc_status_name[cc2]);
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1457  
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1458  	return ret;
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1459  }
c034a43e drivers/staging/typec/fusb302/fusb302.c Yueyao Zhu 2017-04-27  1460  

:::::: The code at line 1413 was first introduced by commit
:::::: c034a43e72dda58e4a184d71f5502ef356e04453 staging: typec: Fairchild FUSB302 Type-c chip driver

:::::: TO: Yueyao Zhu <yueyao@google.com>
:::::: CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
-------------- next part --------------
A non-text attachment was scrubbed...
Name: .config.gz
Type: application/gzip
Size: 30857 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20180610/f9900427/attachment-0001.gz>

  parent reply	other threads:[~2018-06-10 15:50 UTC|newest]

Thread overview: 63+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-05  8:13 [RESEND PATCH v5 0/4] kernel hacking: GCC optimization for better debug experience (-Og) changbin.du
2018-06-05  8:13 ` changbin.du at intel.com
2018-06-05  8:13 ` [PATCH v5 1/4] x86/mm: surround level4_kernel_pgt with #ifdef CONFIG_X86_5LEVEL...#endif changbin.du
2018-06-05  8:13   ` changbin.du at intel.com
2018-06-05  8:13 ` [PATCH v5 2/4] kernel hacking: new config NO_AUTO_INLINE to disable compiler auto-inline optimizations changbin.du
2018-06-05  8:13   ` changbin.du at intel.com
2018-06-05 21:21   ` kbuild test robot
2018-06-05 21:21     ` kbuild test robot
2018-06-05 21:21     ` kbuild test robot
2018-06-05 21:21     ` kbuild test robot
2018-06-06 13:57     ` Steven Rostedt
2018-06-06 13:57       ` Steven Rostedt
2018-06-06 14:26       ` Johan Hovold
2018-06-06 14:26         ` Johan Hovold
2018-06-06 18:26         ` Steven Rostedt
2018-06-06 18:26           ` Steven Rostedt
2018-06-07  4:17           ` Viresh Kumar
2018-06-07  4:17             ` Viresh Kumar
2018-06-07  7:46             ` Du, Changbin
2018-06-07  7:46               ` Du, Changbin
2018-06-07  8:38               ` Viresh Kumar
2018-06-07  8:38                 ` Viresh Kumar
2018-06-07  9:03                 ` Bernd Petrovitsch
2018-06-07  9:03                   ` Bernd Petrovitsch
2018-06-07  9:03                   ` Bernd Petrovitsch
2018-06-07  9:10                   ` Viresh Kumar
2018-06-07  9:10                     ` Viresh Kumar
2018-06-07  9:18                     ` Johan Hovold
2018-06-07  9:18                       ` Johan Hovold
2018-06-07  9:19                       ` Viresh Kumar
2018-06-07  9:19                         ` Viresh Kumar
2018-06-07 10:12                         ` Alex Elder
2018-06-07 10:12                           ` Alex Elder
2018-06-07 10:27                           ` Johan Hovold
2018-06-07 10:27                             ` Johan Hovold
2018-06-07 10:27                             ` Johan Hovold
2018-06-08 20:03                       ` Steven Rostedt
2018-06-08 20:03                         ` Steven Rostedt
2018-06-11 15:46                         ` Johan Hovold
2018-06-11 15:46                           ` Johan Hovold
2018-06-07  8:06             ` Johan Hovold
2018-06-07  8:06               ` Johan Hovold
2018-06-05 21:34   ` kbuild test robot
2018-06-05 21:34     ` kbuild test robot
2018-06-05 21:34     ` kbuild test robot
2018-06-05 21:34     ` kbuild test robot
2018-06-06 14:01     ` Steven Rostedt
2018-06-06 14:01       ` Steven Rostedt
2018-06-05  8:13 ` [PATCH v5 3/4] ARM: mm: fix build error in fix_to_virt with CONFIG_CC_OPTIMIZE_FOR_DEBUGGING changbin.du
2018-06-05  8:13   ` changbin.du at intel.com
2018-06-05  8:13 ` [PATCH v5 4/4] kernel hacking: new config CC_OPTIMIZE_FOR_DEBUGGING to apply GCC -Og optimization changbin.du
2018-06-05  8:13   ` changbin.du at intel.com
2018-06-10 10:44   ` kbuild test robot
2018-06-10 10:44     ` kbuild test robot
2018-06-10 10:44     ` kbuild test robot
2018-06-10 10:44     ` kbuild test robot
2018-06-10 15:49   ` kbuild test robot [this message]
2018-06-10 15:49     ` kbuild test robot
2018-06-10 15:49     ` kbuild test robot
2018-06-10 15:49     ` kbuild test robot
2018-06-11 16:00     ` Steven Rostedt
2018-06-11 16:00       ` Steven Rostedt
  -- strict thread matches above, loose matches on Subject: below --
2018-05-11  8:09 [PATCH v5 0/4] kernel hacking: GCC optimization for better debug experience (-Og) changbin.du
2018-05-11  8:09 ` [PATCH v5 4/4] kernel hacking: new config CC_OPTIMIZE_FOR_DEBUGGING to apply GCC -Og optimization changbin.du

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=201806101929.E2oiistg%fengguang.wu@intel.com \
    --to=lkp@intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=arnd@arndb.de \
    --cc=broonie@kernel.org \
    --cc=changbin.du@gmail.com \
    --cc=changbin.du@intel.com \
    --cc=kbuild-all@01.org \
    --cc=lgirdwood@gmail.com \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-sparse@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=michal.lkml@markovi.net \
    --cc=mingo@redhat.com \
    --cc=rdunlap@infradead.org \
    --cc=rostedt@goodmis.org \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    --cc=yamada.masahiro@socionext.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.