Re: [PATCH] usb: typec: intel_pmc_mux: combine kzalloc + kcalloc

Rosen Penev
2026-04-13T19:47:15Z

On Mon, Apr 13, 2026 at 1:52 AM kernel test robot <lkp@intel.com> wrote:
>
> Hi Rosen,
>
> kernel test robot noticed the following build warnings:
>
> [auto build test WARNING on usb/usb-testing]
> [also build test WARNING on usb/usb-next usb/usb-linus westeri-thunderbolt/next linus/master v7.0-rc7 next-20260410]
> [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/Rosen-Penev/usb-typec-intel_pmc_mux-combine-kzalloc-kcalloc/20260412-223212
> base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
> patch link: https://lore.kernel.org/r/20260411023642.146890-1-rosenp%40gmail.com
> patch subject: [PATCH] usb: typec: intel_pmc_mux: combine kzalloc + kcalloc
> config: x86_64-allmodconfig (https://download.01.org/0day-ci/archive/20260413/202604131654.9GEXISW5-lkp@intel.com/config)
> compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260413/202604131654.9GEXISW5-lkp@intel.com/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 <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202604131654.9GEXISW5-lkp@intel.com/
>
> All warnings (new ones prefixed by >>):
>
> >> drivers/usb/typec/mux/intel_pmc_mux.c:740:3: warning: variable 'num_ports' is uninitialized when used here [-Wuninitialized]
> 740 | num_ports++;
> | ^~~~~~~~~
> drivers/usb/typec/mux/intel_pmc_mux.c:735:14: note: initialize the variable 'num_ports' to silence this warning
> 735 | u8 num_ports;
> | ^
> | = '\0'
> 1 warning generated.
Yikes I forgot to do this. As the merge window is closed I assume this
needs to wait.
>
>
> vim +/num_ports +740 drivers/usb/typec/mux/intel_pmc_mux.c
>
> 730
> 731 static int pmc_usb_probe(struct platform_device *pdev)
> 732 {
> 733 struct fwnode_handle *fwnode = NULL;
> 734 struct pmc_usb *pmc;
> 735 u8 num_ports;
> 736 int i = 0;
> 737 int ret;
> 738
> 739 device_for_each_child_node(&pdev->dev, fwnode)
> > 740 num_ports++;
> 741
> 742 /* The IOM microcontroller has a limitation of max 4 ports. */
> 743 if (num_ports > 4) {
> 744 dev_err(&pdev->dev, "driver limited to 4 ports\n");
> 745 return -ERANGE;
> 746 }
> 747
> 748 pmc = devm_kzalloc(&pdev->dev, struct_size(pmc, port, num_ports),
> 749 GFP_KERNEL);
> 750 if (!pmc)
> 751 return -ENOMEM;
> 752
> 753 pmc->num_ports = num_ports;
> 754
> 755 pmc->ipc = devm_intel_scu_ipc_dev_get(&pdev->dev);
> 756 if (!pmc->ipc)
> 757 return -EPROBE_DEFER;
> 758
> 759 pmc->dev = &pdev->dev;
> 760
> 761 ret = pmc_usb_probe_iom(pmc);
> 762 if (ret)
> 763 return ret;
> 764
> 765 pmc->dentry = debugfs_create_dir(dev_name(pmc->dev), pmc_mux_debugfs_root);
> 766
> 767 /*
> 768 * For every physical USB connector (USB2 and USB3 combo) there is a
> 769 * child ACPI device node under the PMC mux ACPI device object.
> 770 */
> 771 for (i = 0; i < pmc->num_ports; i++) {
> 772 fwnode = device_get_next_child_node(pmc->dev, fwnode);
> 773 if (!fwnode)
> 774 break;
> 775
> 776 ret = pmc_usb_register_port(pmc, i, fwnode);
> 777 if (ret) {
> 778 fwnode_handle_put(fwnode);
> 779 goto err_remove_ports;
> 780 }
> 781
> 782 pmc_mux_port_debugfs_init(&pmc->port[i]);
> 783 }
> 784
> 785 platform_set_drvdata(pdev, pmc);
> 786
> 787 return 0;
> 788
> 789 err_remove_ports:
> 790 for (i = 0; i < pmc->num_ports; i++) {
> 791 typec_switch_unregister(pmc->port[i].typec_sw);
> 792 typec_mux_unregister(pmc->port[i].typec_mux);
> 793 usb_role_switch_unregister(pmc->port[i].usb_sw);
> 794 }
> 795
> 796 acpi_dev_put(pmc->iom_adev);
> 797
> 798 debugfs_remove(pmc->dentry);
> 799
> 800 return ret;
> 801 }
> 802
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki