Sourabh Jain [off-list ref] writes:

This issue only occurs with the Radix MMU.
Booting the same kernel with disable_radix=1 does not reproduce the issue.

The system also has pmem.

@Sourabh,

Few requests -
1. Could you also attach the boot logs from the same system with the
   same kernel but with disable_radix=1?

2. I can't really tell on how is MMU related to this issue? But I think
   if you could share the working dmesg logs from Hash that might give
   some more info. I am suspecting what if the firmware negotiates
   different page sizes even for TCEs for Radix v/s Hash.

3. Would it be possible for you to try git bisect and identify the
   culprit commit?


Btw, to clarify I think there are two issues here:
1. EEH triggered for the USB adapter - I think you meant that with Hash
   you don't even see EEH error being triggered at all. 

2. Second problem is - EEH recovery causing this WARNING.

[   17.375534] [    T118] WARNING: arch/powerpc/kernel/eeh_pe.c:439 at eeh_pe_tree_remove+0xf8/0x2f0, CPU#10: eehd/118
<...>
[   17.375599] [    T118] CPU: 10 UID: 0 PID: 118 Comm: eehd Tainted: G            E       7.2.0-rc3upstream+ #3 PREEMPT(lazy)  f29942c1738362234fefd88de0d1ed711f1a557e
[   17.375603] [    T118] Tainted: [E]=UNSIGNED_MODULE
[   17.375604] [    T118] Hardware name: IBM,9080-HEX Power11 (architected) 0x820200 0xf000007 of:IBM,FW1120.00 (NH1120_135) hv:phyp pSeries
<...>
[   17.375650] [    T118] NIP [c00000000004a048] eeh_pe_tree_remove+0xf8/0x2f0
[   17.375654] [    T118] LR [c00000000004ba6c] eeh_pe_detach_dev+0x5c/0xa0
[   17.375658] [    T118] Call Trace:
[   17.375659] [    T118] [c00000000a357c90] [c00000000dd32800] 0xc00000000dd32800 (unreliable)
[   17.375668] [    T118] [c00000000a357d30] [c00000000004ba6c] eeh_pe_detach_dev+0x5c/0xa0
[   17.375672] [    T118] [c00000000a357d60] [c0000000000496ec] eeh_pe_traverse+0x6c/0xf0
[   17.375676] [    T118] [c00000000a357da0] [c00000000004e100] eeh_reset_device+0x1f8/0x298
[   17.375680] [    T118] [c00000000a357e50] [c00000000004ce5c] eeh_handle_normal_event+0x61c/0xa60
[   17.375685] [    T118] [c00000000a357f30] [c00000000004e298] eeh_event_handler+0xf8/0x190
[   17.375689] [    T118] [c00000000a357f90] [c00000000025dab4] kthread+0x194/0x1b0


-ritesh