PCI: Race condition in pci_create_sysfs_dev_files (can't boot)

["Krzysztof Hałasa" <khalasa@piap.pl>]

Pali, et al,

I'm encountering a problem booting an i.MX6-based device (Gateworks
Ventana SBC). This is apparently a known issue:
https://lkml.org/lkml/2020/7/16/388

Do you guys know of a fix for this? Booting this machine reliably is
lately impossible.

First, it spews a warning:

pcieport 0000:00:00.0: PME: Signaling with IRQ 310

sysfs: cannot create duplicate filename '/devices/platform/soc/1ffc000.pcie/pci0000:00/0000:00:00.0/0000:e0'
CPU: 2 PID: 7 Comm: kworker/u8:0 Not tainted 5.14.0-rc3+ #40
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Workqueue: events_unbound async_run_entry_fn

unwind_backtrace from show_stack+0x10/0x14
show_stack from dump_stack_lvl+0x40/0x4c
dump_stack_lvl from sysfs_warn_dup+0x54/0x60
sysfs_warn_dup from sysfs_add_file_mode_ns+0x154/0x1a8
sysfs_add_file_mode_ns from sysfs_create_bin_file+0x60/0x8c
sysfs_create_bin_file from pci_create_resource_files+0xf4/0x140
pci_create_resource_files from pci_bus_add_device+0x20/0x8c
pci_bus_add_device from pci_bus_add_devices+0x3c/0x80
pci_bus_add_devices from pci_bus_add_devices+0x70/0x80
pci_bus_add_devices from pci_host_probe+0x3c/0x90
pci_host_probe from dw_pcie_host_init+0x200/0x4b4
dw_pcie_host_init from imx6_pcie_probe+0x338/0x668
imx6_pcie_probe from platform_probe+0x80/0xc0
platform_probe from really_probe+0x158/0x324
really_probe from __driver_probe_device+0x84/0xe4
__driver_probe_device from driver_probe_device+0x34/0xd0
driver_probe_device from __driver_attach_async_helper+0x20/0x38
__driver_attach_async_helper from async_run_entry_fn+0x24/0xb4
async_run_entry_fn from process_one_work+0x164/0x3b0
process_one_work from worker_thread+0x2c/0x52c
worker_thread from kthread+0x110/0x154
kthread from ret_from_fork+0x14/0x24

pcieport 0000:01:00.0: enabling device (0140 -> 0143)

Then:
Unable to handle kernel paging request at virtual address 6f736572 (ASCII = "reso")
pgd = (ptrval)
[6f736572] *pgd=00000000
Internal error: Oops: 5 [#1] SMP ARM
Modules linked in:
CPU: 2 PID: 7 Comm: kworker/u8:0 Not tainted 5.14.0-rc3+ #40
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Workqueue: events_unbound async_run_entry_fn
PC is at string_nocheck+0x20/0xa0
LR is at string+0x54/0x64
Process kworker/u8:0 (pid: 7, stack limit = 0x(ptrval))

string_nocheck from string+0x54/0x64
string from vsnprintf+0x1c4/0x48c
vsnprintf from vprintk_store+0x80/0x33c
vprintk_store from vprintk_emit+0x6c/0x1e0
vprintk_emit from vprintk_default+0x20/0x28
vprintk_default from printk+0x1c/0x2c
printk from sysfs_warn_dup+0x50/0x60
sysfs_warn_dup from sysfs_add_file_mode_ns+0x154/0x1a8
sysfs_add_file_mode_ns from sysfs_create_bin_file+0x60/0x8c
sysfs_create_bin_file from pci_create_resource_files+0xf4/0x140
pci_create_resource_files from pci_bus_add_device+0x20/0x8c
pci_bus_add_device from pci_bus_add_devices+0x3c/0x80
pci_bus_add_devices from pci_bus_add_devices+0x70/0x80
pci_bus_add_devices from pci_host_probe+0x3c/0x90
pci_host_probe from dw_pcie_host_init+0x200/0x4b4
dw_pcie_host_init from imx6_pcie_probe+0x338/0x668
imx6_pcie_probe from platform_probe+0x80/0xc0
platform_probe from really_probe+0x158/0x324
really_probe from __driver_probe_device+0x84/0xe4
__driver_probe_device from driver_probe_device+0x34/0xd0
driver_probe_device from __driver_attach_async_helper+0x20/0x38
__driver_attach_async_helper from async_run_entry_fn+0x24/0xb4
async_run_entry_fn from process_one_work+0x164/0x3b0
process_one_work from worker_thread+0x2c/0x52c
worker_thread from kthread+0x110/0x154
kthread from ret_from_fork+0x14/0x24
Code: e1dd42b2 e58d301c e3540000 0a000019 (e5d2e000)
--
Krzysztof "Chris" Hałasa

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