tree: https://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/next-queue.git dev-queue head: bb74886dd020cb7d62869fc4a57c50b8bda718ad commit: 4cbe66aa3a43a5910d9afe165b726711438d3612 [36/44] igc: Add initial LTR support config: s390-randconfig-r023-20200607 (attached as .config) compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project e429cffd4f228f70c1d9df0e5d77c08590dd9766) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install s390 cross compiling tool for clang build # apt-get install binutils-s390-linux-gnu git checkout 4cbe66aa3a43a5910d9afe165b726711438d3612 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=s390 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32' ___constant_swab32(x) : ^ include/uapi/linux/swab.h:19:12: note: expanded from macro '___constant_swab32' (((__u32)(x) & (__u32)0x000000ffUL) << 24) | ^ In file included from drivers/net/ethernet/intel/igc/igc_mac.c:4: In file included from include/linux/pci.h:39: In file included from include/linux/io.h:13: In file included from arch/s390/include/asm/io.h:72: include/asm-generic/io.h:492:45: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32' ___constant_swab32(x) : ^ include/uapi/linux/swab.h:20:12: note: expanded from macro '___constant_swab32' (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | ^ In file included from drivers/net/ethernet/intel/igc/igc_mac.c:4: In file included from include/linux/pci.h:39: In file included from include/linux/io.h:13: In file included from arch/s390/include/asm/io.h:72: include/asm-generic/io.h:492:45: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32' ___constant_swab32(x) : ^ include/uapi/linux/swab.h:21:12: note: expanded from macro '___constant_swab32' (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | ^ In file included from drivers/net/ethernet/intel/igc/igc_mac.c:4: In file included from include/linux/pci.h:39: In file included from include/linux/io.h:13: In file included from arch/s390/include/asm/io.h:72: include/asm-generic/io.h:492:45: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32' ___constant_swab32(x) : ^ include/uapi/linux/swab.h:22:12: note: expanded from macro '___constant_swab32' (((__u32)(x) & (__u32)0xff000000UL) >> 24))) ^ In file included from drivers/net/ethernet/intel/igc/igc_mac.c:4: In file included from include/linux/pci.h:39: In file included from include/linux/io.h:13: In file included from arch/s390/include/asm/io.h:72: include/asm-generic/io.h:492:45: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:120:12: note: expanded from macro '__swab32' __fswab32(x)) ^ In file included from drivers/net/ethernet/intel/igc/igc_mac.c:4: In file included from include/linux/pci.h:39: In file included from include/linux/io.h:13: In file included from arch/s390/include/asm/io.h:72: include/asm-generic/io.h:503:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writeb(value, PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:513:46: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writew(cpu_to_le16(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:523:46: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writel(cpu_to_le32(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:585:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:593:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:601:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:610:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:619:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:628:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ if (!mac->get_link_status) { ^~~~~~~~~~~~~~~~~~~~~ drivers/net/ethernet/intel/igc/igc_mac.c:423:33: note: uninitialized use occurs here ret_val = igc_set_ltr_i225(hw, link); ^~~~ drivers/net/ethernet/intel/igc/igc_mac.c:373:2: note: remove the 'if' if its condition is always false if (!mac->get_link_status) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/net/ethernet/intel/igc/igc_mac.c:366:11: note: initialize the variable 'link' to silence this warning bool link; ^ = 0 21 warnings generated. vim +373 drivers/net/ethernet/intel/igc/igc_mac.c ab4056126813c8 Sasha Neftin 2018-10-11 353 ab4056126813c8 Sasha Neftin 2018-10-11 354 /** ab4056126813c8 Sasha Neftin 2018-10-11 355 * igc_check_for_copper_link - Check for link (Copper) ab4056126813c8 Sasha Neftin 2018-10-11 356 * @hw: pointer to the HW structure ab4056126813c8 Sasha Neftin 2018-10-11 357 * ab4056126813c8 Sasha Neftin 2018-10-11 358 * Checks to see of the link status of the hardware has changed. If a ab4056126813c8 Sasha Neftin 2018-10-11 359 * change in link status has been detected, then we read the PHY registers ab4056126813c8 Sasha Neftin 2018-10-11 360 * to get the current speed/duplex if link exists. ab4056126813c8 Sasha Neftin 2018-10-11 361 */ ab4056126813c8 Sasha Neftin 2018-10-11 362 s32 igc_check_for_copper_link(struct igc_hw *hw) ab4056126813c8 Sasha Neftin 2018-10-11 363 { ab4056126813c8 Sasha Neftin 2018-10-11 364 struct igc_mac_info *mac = &hw->mac; ab4056126813c8 Sasha Neftin 2018-10-11 365 s32 ret_val; ab4056126813c8 Sasha Neftin 2018-10-11 366 bool link; ab4056126813c8 Sasha Neftin 2018-10-11 367 ab4056126813c8 Sasha Neftin 2018-10-11 368 /* We only want to go out to the PHY registers to see if Auto-Neg ab4056126813c8 Sasha Neftin 2018-10-11 369 * has completed and/or if our link status has changed. The ab4056126813c8 Sasha Neftin 2018-10-11 370 * get_link_status flag is set upon receiving a Link Status ab4056126813c8 Sasha Neftin 2018-10-11 371 * Change or Rx Sequence Error interrupt. ab4056126813c8 Sasha Neftin 2018-10-11 372 */ ab4056126813c8 Sasha Neftin 2018-10-11 @373 if (!mac->get_link_status) { ab4056126813c8 Sasha Neftin 2018-10-11 374 ret_val = 0; ab4056126813c8 Sasha Neftin 2018-10-11 375 goto out; ab4056126813c8 Sasha Neftin 2018-10-11 376 } ab4056126813c8 Sasha Neftin 2018-10-11 377 ab4056126813c8 Sasha Neftin 2018-10-11 378 /* First we want to see if the MII Status Register reports ab4056126813c8 Sasha Neftin 2018-10-11 379 * link. If so, then we want to get the current speed/duplex ab4056126813c8 Sasha Neftin 2018-10-11 380 * of the PHY. ab4056126813c8 Sasha Neftin 2018-10-11 381 */ 5586838fe9ced0 Sasha Neftin 2018-10-11 382 ret_val = igc_phy_has_link(hw, 1, 0, &link); ab4056126813c8 Sasha Neftin 2018-10-11 383 if (ret_val) ab4056126813c8 Sasha Neftin 2018-10-11 384 goto out; ab4056126813c8 Sasha Neftin 2018-10-11 385 ab4056126813c8 Sasha Neftin 2018-10-11 386 if (!link) ab4056126813c8 Sasha Neftin 2018-10-11 387 goto out; /* No link detected */ ab4056126813c8 Sasha Neftin 2018-10-11 388 ab4056126813c8 Sasha Neftin 2018-10-11 389 mac->get_link_status = false; ab4056126813c8 Sasha Neftin 2018-10-11 390 ab4056126813c8 Sasha Neftin 2018-10-11 391 /* Check if there was DownShift, must be checked ab4056126813c8 Sasha Neftin 2018-10-11 392 * immediately after link-up ab4056126813c8 Sasha Neftin 2018-10-11 393 */ 5586838fe9ced0 Sasha Neftin 2018-10-11 394 igc_check_downshift(hw); ab4056126813c8 Sasha Neftin 2018-10-11 395 ab4056126813c8 Sasha Neftin 2018-10-11 396 /* If we are forcing speed/duplex, then we simply return since ab4056126813c8 Sasha Neftin 2018-10-11 397 * we have already determined whether we have link or not. ab4056126813c8 Sasha Neftin 2018-10-11 398 */ ab4056126813c8 Sasha Neftin 2018-10-11 399 if (!mac->autoneg) { ab4056126813c8 Sasha Neftin 2018-10-11 400 ret_val = -IGC_ERR_CONFIG; ab4056126813c8 Sasha Neftin 2018-10-11 401 goto out; ab4056126813c8 Sasha Neftin 2018-10-11 402 } ab4056126813c8 Sasha Neftin 2018-10-11 403 ab4056126813c8 Sasha Neftin 2018-10-11 404 /* Auto-Neg is enabled. Auto Speed Detection takes care ab4056126813c8 Sasha Neftin 2018-10-11 405 * of MAC speed/duplex configuration. So we only need to ab4056126813c8 Sasha Neftin 2018-10-11 406 * configure Collision Distance in the MAC. ab4056126813c8 Sasha Neftin 2018-10-11 407 */ ab4056126813c8 Sasha Neftin 2018-10-11 408 igc_config_collision_dist(hw); ab4056126813c8 Sasha Neftin 2018-10-11 409 ab4056126813c8 Sasha Neftin 2018-10-11 410 /* Configure Flow Control now that Auto-Neg has completed. ab4056126813c8 Sasha Neftin 2018-10-11 411 * First, we need to restore the desired flow control ab4056126813c8 Sasha Neftin 2018-10-11 412 * settings because we may have had to re-autoneg with a ab4056126813c8 Sasha Neftin 2018-10-11 413 * different link partner. ab4056126813c8 Sasha Neftin 2018-10-11 414 */ 4eb8080143a9d9 Sasha Neftin 2018-10-11 415 ret_val = igc_config_fc_after_link_up(hw); ab4056126813c8 Sasha Neftin 2018-10-11 416 if (ret_val) ab4056126813c8 Sasha Neftin 2018-10-11 417 hw_dbg("Error configuring flow control\n"); ab4056126813c8 Sasha Neftin 2018-10-11 418 ab4056126813c8 Sasha Neftin 2018-10-11 419 out: 4cbe66aa3a43a5 Sasha Neftin 2020-06-02 420 /* Now that we are aware of our link settings, we can set the LTR 4cbe66aa3a43a5 Sasha Neftin 2020-06-02 421 * thresholds. 4cbe66aa3a43a5 Sasha Neftin 2020-06-02 422 */ 4cbe66aa3a43a5 Sasha Neftin 2020-06-02 423 ret_val = igc_set_ltr_i225(hw, link); 4cbe66aa3a43a5 Sasha Neftin 2020-06-02 424 ab4056126813c8 Sasha Neftin 2018-10-11 425 return ret_val; ab4056126813c8 Sasha Neftin 2018-10-11 426 } ab4056126813c8 Sasha Neftin 2018-10-11 427 :::::: The code at line 373 was first introduced by commit :::::: ab4056126813c889ee6c8fb24ca8f75b84c981ab igc: Add NVM support :::::: TO: Sasha Neftin <sasha.neftin(a)intel.com&gt; :::::: CC: Jeff Kirsher <jeffrey.t.kirsher(a)intel.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org