Re: TPM V2: kernel panic on linux reboot

[Jarkko Sakkinen <jarkko@kernel.org>]

On Fri, Feb 12, 2021 at 07:20:02AM +0000, florian.manoel@siemens.com wrote:
> Hi,
> 
> => Last update and happy end
> 
> To remember what the issue was : kernel panic on reboot on a custom board equipped with CPU NXP LS1043a and TMP V2.0 Infineon slb9670 (spi interface).
> What we did but didn't fix the issue : update our kernel to 5.10.8 => panic still occurs
> What we did and fix the issue => use this patch : https://lkml.org/lkml/2020/7/9/1242

Andrey,

I re-read the thread, and it's been a while and I'm not sure if
I fully get my old review comments.

Your commit message refers to these commits:

A. b4c6230bb0ba spi: Fix controller unregister order
B. f40913d2dca1 spi: pxa2xx: Fix controller unregister order

So I presume that either A or B causes this sequence to trigger:

1. tpm_class_shutdown()
2. tpm_del_char_device()

... and either A or B causes this sequence to trigger:

1. tpm_class_shutdown()
2. tpm_del_char_device()

So:

- Does that fix bundle two separate bug fixes, and if yes, which
  on is associated with which?
- Why do they cause the sequences to trigger, and why these sequences
  did not trigger before?

/Jarkko