On Mon, Nov 08, 2021 at 08:06:26PM +0200, Andy Shevchenko wrote: > Btw, what you can do in this case is to switch to use fwnode_create_software > node and switch them in drd.c. It will be much much easier to achieve then > full kernel refactoring. (Adding arm64 and dwc3 people since that iort_iommu_configure_id() path below to create a duplicated sysfs is arm64-specific. The original thread is here): https://lore.kernel.org/lkml/20211101200346.16466-1-quic_qiancai@xxxxxxxxxxx/ Andy, did you mean host.c? I saw that the first time "/devices/platform/808622B7:01/xhci-hcd.3.auto/software_node" was created by dwc3_host_init(). Call trace: sysfs_do_create_link_sd.isra.0 sysfs_create_link software_node_notify device_add platform_device_add dwc3_host_init dwc3_probe platform_probe really_probe.part.0 really_probe __driver_probe_device driver_probe_device __driver_attach bus_for_each_dev driver_attach bus_add_driver driver_register __platform_driver_register dwc3_driver_init dwc3_driver_init at drivers/usb/dwc3/core.c:2072 do_one_initcall kernel_init_freeable kernel_init ret_from_fork Then, which functions do you suggest to replace with fwnode_create_software_node()? In dwc3_host_init(), int dwc3_host_init(struct dwc3 *dwc) { ... xhci = platform_device_alloc("xhci-hcd", PLATFORM_DEVID_AUTO); ... ret = platform_device_add(xhci); I am wondering if that we could solve the problem by avoiding "xhci-hcd" string here which would unfortunately clash with xhci_plat_init() as mentioned before: sysfs_create_link software_node_notify device_create_managed_software_node iort_named_component_init iort_iommu_configure_id acpi_dma_configure_id platform_dma_configure really_probe.part.0 really_probe __driver_probe_device driver_probe_device __driver_attach bus_for_each_dev driver_attach bus_add_driver driver_register __platform_driver_register xhci_plat_init do_one_initcall kernel_init_freeable kernel_init ret_from_fork since the driver would also use "xhci-hcd". static struct platform_driver usb_xhci_driver = { ... .driver = { .name = "xhci-hcd", static int __init xhci_plat_init(void) { ... return platform_driver_register(&usb_xhci_driver); BTW, "/sys/devices/platform/808622B7:01/software_node" was also created from the path: sysfs_create_link software_node_notify device_create_managed_software_node iort_named_component_init iort_iommu_configure_id acpi_dma_configure_id platform_dma_configure really_probe.part.0 really_probe __driver_probe_device driver_probe_device __driver_attach bus_for_each_dev driver_attach bus_add_driver driver_register __platform_driver_register dwc3_driver_init do_one_initcall kernel_init_freeable kernel_init ret_from_fork # ls -l /sys//devices/platform/808622B7:01/xhci-hcd.3.auto/software_node lrwxrwxrwx 1 root root 0 Nov 9 03:18 /sys//devices/platform/808622B7:01/xhci-hcd.3.auto/software_node -> ../../../../kernel/software_nodes/node4 # ls -l /sys//devices/platform/808622B7:01/software_node lrwxrwxrwx 1 root root 0 Nov 9 03:18 /sys//devices/platform/808622B7:01/software_node -> ../../../kernel/software_nodes/node4
