Subject: Re: [PATCH] error path improvement in dlpar add

From: kernel test robot <[email-masked]>
Date: Tue, 27 Jan 2026 18:53:12 +0800

Hi,

kernel test robot noticed the following build warnings:

[auto build test WARNING on powerpc/next]
[also build test WARNING on powerpc/fixes linus/master v6.19-rc7 next-20260126]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/wenxiong-linux-ibm-com/error-path-improvement-in-dlpar-add/20260127-121714
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
patch link:    https://lore.kernel.org/r/20260127021845.2326-1-wenxiong%40linux.ibm.com
patch subject: [PATCH] error path improvement in dlpar add
config: powerpc-allyesconfig (https://download.01.org/0day-ci/archive/20260127/[email-masked]/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 9b8addffa70cee5b2acc5454712d9cf78ce45710)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260127/[email-masked]/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email-masked]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email-masked]/

All warnings (new ones prefixed by >>):

>> arch/powerpc/kernel/pci-hotplug.c:182:12: warning: more '%' conversions than data arguments [-Wformat-insufficient-args]
     182 |                 pr_err("%s: unable to add hotplug pci device!\n");
         |                         ~^
   include/linux/printk.h:555:25: note: expanded from macro 'pr_err'
     555 |         printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
         |                                ^~~
   include/linux/printk.h:402:21: note: expanded from macro 'pr_fmt'
     402 | #define pr_fmt(fmt) fmt
         |                     ^~~
   include/linux/printk.h:512:53: note: expanded from macro 'printk'
     512 | #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__)
         |                                                     ^~~
   include/linux/printk.h:484:11: note: expanded from macro 'printk_index_wrap'
     484 |                 _p_func(_fmt, ##__VA_ARGS__);                           \
         |                         ^~~~
   1 warning generated.

vim +182 arch/powerpc/kernel/pci-hotplug.c

   125	
   126	/**
   127	 * pci_hp_add_devices - adds new pci devices to bus
   128	 * @bus: the indicated PCI bus
   129	 *
   130	 * This routine will find and fixup new pci devices under
   131	 * the indicated bus. This routine presumes that there
   132	 * might already be some devices under this bridge, so
   133	 * it carefully tries to add only new devices.  (And that
   134	 * is how this routine differs from other, similar pcibios
   135	 * routines.)
   136	 */
   137	void pci_hp_add_devices(struct pci_bus *bus)
   138	{
   139		int mode, max;
   140		struct pci_dev *dev;
   141		struct pci_controller *phb;
   142		struct device_node *dn = pci_bus_to_OF_node(bus);
   143		int ret = 0;
   144	
   145		if (!dn)
   146			return;
   147	
   148		phb = pci_bus_to_host(bus);
   149	
   150		mode = PCI_PROBE_NORMAL;
   151		if (phb->controller_ops.probe_mode)
   152			mode = phb->controller_ops.probe_mode(bus);
   153	
   154		if (mode == PCI_PROBE_DEVTREE) {
   155			/* use ofdt-based probe */
   156			of_rescan_bus(dn, bus);
   157		} else if (mode == PCI_PROBE_NORMAL &&
   158			   dn->child && PCI_DN(dn->child)) {
   159			/*
   160			 * Use legacy probe. In the partial hotplug case, we
   161			 * probably have grandchildren devices unplugged. So
   162			 * we don't check the return value from pci_scan_slot() in
   163			 * order for fully rescan all the way down to pick them up.
   164			 * They can have been removed during partial hotplug.
   165			 */
   166			traverse_siblings_and_scan_slot(dn, bus);
   167			max = bus->busn_res.start;
   168			/*
   169			 * Scan bridges that are already configured. We don't touch
   170			 * them unless they are misconfigured (which will be done in
   171			 * the second scan below).
   172			 */
   173			for_each_pci_bridge(dev, bus)
   174				max = pci_scan_bridge(bus, dev, max, 0);
   175	
   176			/* Scan bridges that need to be reconfigured */
   177			for_each_pci_bridge(dev, bus)
   178				max = pci_scan_bridge(bus, dev, max, 1);
   179		}
   180		ret = pcibios_finish_adding_to_bus(bus);
   181		if (ret)
 > 182			pr_err("%s: unable to add hotplug pci device!\n");

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki