eeh-basic.sh in P8 break with f-hwe-5.15 : Failed to recover

[Thibf]

== Original Bug Report ==
Issue found on 5.15.0-79.86, Focal P8 "Dryden"

Running 'make run_tests -C powerpc/eeh TEST_PROGS=eeh-basic.sh TEST_GEN_PROGS='' TEST_CUSTOM_PROGS='''
make: Entering directory '/home/ubuntu/autotest/client/tmp/ubuntu_kernel_selftests/src/linux/tools/testing/selftests/powerpc/eeh'
TAP version 13
1..1
# selftests: powerpc/eeh: eeh-basic.sh
# 0000:00:00.0, Skipped: bridge
# 0000:01:00.0, Skipped: bridge
# 0000:02:01.0, Skipped: bridge
# 0000:02:02.0, Skipped: bridge
# 0001:00:00.0, Skipped: bridge
# 0001:01:00.0, Skipped: bridge
# 0001:02:01.0, Skipped: bridge
# 0001:02:08.0, Skipped: bridge
# 0001:02:09.0, Skipped: bridge
# 0001:02:0a.0, Skipped: bridge
# 0001:02:0b.0, Skipped: bridge
# 0001:02:0c.0, Skipped: bridge
# 0001:03:00.0, Added
# 0001:09:00.0, Added
# 0001:0a:00.0, Skipped: ahci doesn't support recovery
# 0001:0b:00.0, Skipped: bridge
# 0001:0c:00.0, Added
# 0001:0d:00.0, Skipped: ahci doesn't support recovery
# 0002:00:00.0, Skipped: bridge
# 0002:01:00.0, Added
# 0020:00:00.0, Skipped: bridge
# 0021:00:00.0, Skipped: bridge
# 0022:00:00.0, Skipped: bridge
# 0022:01:00.0, Skipped: bridge
# 0022:02:01.0, Skipped: bridge
# 0022:02:02.0, Skipped: bridge
# Found 4 breakable devices...
# Breaking 0001:03:00.0...
# 0001:03:00.0, Recovered after 0 seconds
# Breaking 0001:09:00.0...
# 0001:09:00.0, waited 0/60
# 0001:09:00.0, waited 1/60
# 0001:09:00.0, waited 2/60
# 0001:09:00.0, waited 3/60
# 0001:09:00.0, waited 4/60
# 0001:09:00.0, waited 5/60
# 0001:09:00.0, waited 6/60
# 0001:09:00.0, waited 7/60
# 0001:09:00.0, Recovered after 8 seconds
# Breaking 0001:0c:00.0...
# 0001:0c:00.0, Recovered after 0 seconds
# Breaking 0002:01:00.0...
# 0002:01:00.0, waited 0/60
# 0002:01:00.0, waited 1/60
# 0002:01:00.0, waited 2/60
# 0002:01:00.0, waited 3/60
# 0002:01:00.0, waited 4/60
# 0002:01:00.0, waited 5/60
# 0002:01:00.0, waited 6/60
# 0002:01:00.0, waited 7/60
# 0002:01:00.0, waited 8/60
# 0002:01:00.0, waited 9/60
# 0002:01:00.0, waited 10/60
# 0002:01:00.0, waited 11/60
# 0002:01:00.0, waited 12/60
# 0002:01:00.0, waited 13/60
# 0002:01:00.0, waited 14/60
# 0002:01:00.0, waited 15/60
# 0002:01:00.0, waited 16/60
# 0002:01:00.0, waited 17/60
# 0002:01:00.0, waited 18/60
# 0002:01:00.0, waited 19/60
# 0002:01:00.0, waited 20/60
# 0002:01:00.0, waited 21/60
# 0002:01:00.0, waited 22/60
# 0002:01:00.0, waited 23/60
# 0002:01:00.0, waited 24/60
# 0002:01:00.0, waited 25/60
# 0002:01:00.0, waited 26/60
# 0002:01:00.0, waited 27/60
# 0002:01:00.0, waited 28/60
# 0002:01:00.0, waited 29/60
# 0002:01:00.0, waited 30/60
# 0002:01:00.0, waited 31/60
# 0002:01:00.0, waited 32/60
# 0002:01:00.0, waited 33/60
# 0002:01:00.0, waited 34/60
# 0002:01:00.0, waited 35/60
# 0002:01:00.0, waited 36/60
# 0002:01:00.0, waited 37/60
# 0002:01:00.0, waited 38/60
# 0002:01:00.0, waited 39/60
# 0002:01:00.0, waited 40/60
# 0002:01:00.0, waited 41/60
# 0002:01:00.0, waited 42/60
# 0002:01:00.0, waited 43/60
# 0002:01:00.0, waited 44/60
# 0002:01:00.0, waited 45/60
# 0002:01:00.0, waited 46/60
# 0002:01:00.0, waited 47/60
# 0002:01:00.0, waited 48/60
# 0002:01:00.0, waited 49/60
# 0002:01:00.0, waited 50/60
# 0002:01:00.0, waited 51/60
# 0002:01:00.0, waited 52/60
# 0002:01:00.0, waited 53/60
# 0002:01:00.0, waited 54/60
# 0002:01:00.0, waited 55/60
# 0002:01:00.0, waited 56/60
# 0002:01:00.0, waited 57/60
# 0002:01:00.0, waited 58/60
# 0002:01:00.0, waited 59/60
# 0002:01:00.0, waited 60/60
# 0002:01:00.0, Failed to recover!
# 1 devices failed to recover (4 tested)
# --- /tmp/tmp.YUNO6JOP0Y 2023-07-19 15:41:15.245989338 +0000
# +++ - 2023-07-19 15:43:45.843860483 +0000
# @@ -21,10 +21,10 @@
# 0001:0c:00.0 VGA compatible controller: ASPEED Technology, Inc. ASPEED Graphics Family (rev 30)
# 0001:0d:00.0 SATA controller: Marvell Technology Group Ltd. 88SE9230 PCIe SATA 6Gb/s Controller (rev 11)
# 0002:00:00.0 PCI bridge: IBM POWER8 Host Bridge (PHB3)
# -0002:01:00.0 Ethernet controller: Intel Corporation Ethernet Controller X710/X557-AT 10GBASE-T (rev 02)
# -0002:01:00.1 Ethernet controller: Intel Corporation Ethernet Controller X710/X557-AT 10GBASE-T (rev 02)
# -0002:01:00.2 Ethernet controller: Intel Corporation Ethernet Controller X710/X557-AT 10GBASE-T (rev 02)
# -0002:01:00.3 Ethernet controller: Intel Corporation Ethernet Controller X710/X557-AT 10GBASE-T (rev 02)
# +0002:01:00.0 Ethernet controller: Intel Corporation Ethernet Controller X710/X557-AT 10GBASE-T (rev ff)
# +0002:01:00.1 Ethernet controller: Intel Corporation Ethernet Controller X710/X557-AT 10GBASE-T (rev ff)
# +0002:01:00.2 Ethernet controller: Intel Corporation Ethernet Controller X710/X557-AT 10GBASE-T (rev ff)
# +0002:01:00.3 Ethernet controller: Intel Corporation Ethernet Controller X710/X557-AT 10GBASE-T (rev ff)
# 0020:00:00.0 PCI bridge: IBM POWER8 Host Bridge (PHB3)
# 0021:00:00.0 PCI bridge: IBM POWER8 Host Bridge (PHB3)
# 0022:00:00.0 PCI bridge: IBM POWER8 Host Bridge (PHB3)
not ok 1 selftests: powerpc/eeh: eeh-basic.sh # exit=1

[Luke Nowakowski-Krijger (lukenow)]

hey! I opened another bug for this issue here https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2021748

and narrowed it down to a certain commit but never got around to submitting the revert, or even really figuring out why exactly this change is causing this issue.