[SRU][E][PATCH 0/1] fix igb kernel oops on Dell XPS 13

[Andrea Righi]

BugLink: https://bugs.launchpad.net/bugs/1864754

[Impact]

Disconnecting a thunderbolt docking station on a Dell Inc. XPS 13
9360/0D4J15 can trigger the following oops with the igb driver:

[   99.495863] WARNING: CPU: 1 PID: 44 at /tmp/kernel-arighi-0d8f92abf395-J4zI/build/drivers/net/ethernet/intel/igb/igb_main.c:756 igb_rd32+0x78/0x80 [igb]
...
[   99.495952] Call Trace:
[   99.495956]  igb_release_hw_control+0x1e/0x40 [igb]
[   99.495960]  igb_remove+0x98/0x170 [igb]
[   99.495962]  pci_device_remove+0x3e/0xc0
[   99.495964]  device_release_driver_internal+0xe0/0x1b0
[   99.495965]  device_release_driver+0x12/0x20
[   99.495966]  pci_stop_bus_device+0x68/0x90
[   99.495979]  pci_stop_bus_device+0x30/0x90
[   99.495979]  pci_stop_bus_device+0x42/0x90
[   99.495981]  pci_stop_and_remove_bus_device+0x12/0x20
[   99.495982]  trim_stale_devices+0x167/0x190
[   99.495983]  trim_stale_devices+0xa9/0x190
[   99.495984]  trim_stale_devices+0xbb/0x190
[   99.495985]  ? get_slot_status+0xa2/0x100
[   99.495986]  acpiphp_check_bridge.part.14+0x100/0x140
[   99.495987]  acpiphp_hotplug_notify+0x191/0x1e0
[   99.495988]  ? free_bridge+0x100/0x100
[   99.495989]  acpi_device_hotplug+0xa4/0x4b0
[   99.495990]  acpi_hotplug_work_fn+0x1e/0x30
[   99.495993]  process_one_work+0x1fd/0x3f0
[   99.495994]  worker_thread+0x34/0x410
[   99.495995]  kthread+0x121/0x140
[   99.495996]  ? process_one_work+0x3f0/0x3f0
[   99.495997]  ? kthread_park+0xb0/0xb0
[   99.495999]  ret_from_fork+0x35/0x40
[   99.496000] ---[ end trace 104285530da6f53c ]---

[Test case]

Bug reporter provided the test case by physically disconnecting the docking
station. The problems can be easily reproduced.

[Fix]

Apply upstream commit:

  94bc1e522b32c866d85b5af0ede55026b585ae73 ("igb/igc: Don't warn on fatal read failures when the device is removed")

[Regression potential]

Clean cherry pick, tested on the affected platform with positive result.
Regression potential is minimal.

----------------------------------------------------------------
Lyude Paul (1):
      igb/igc: Don't warn on fatal read failures when the device is removed

 drivers/net/ethernet/intel/igb/igb_main.c | 3 ++-
 drivers/net/ethernet/intel/igc/igc_main.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)