Comment 0 for bug 1827755

---Problem Description---
Normally nx-compress and nx-842-powernv modules are loaded when selects 842-nx compressor if not loaded and execute forever during system execution. So we will not see this bug in normal case.

But we are seeing NX CRB request timeout when uninstall these modules and load them or select 842-nx compressor.

---uname output---
18.04

Machine Type = P9 system

---Steps to Reproduce---
- Install nx-compress and nx-842-powernv modules
- Initiate NX request
- Uninstall these modules
- Initiate NX request again and we get CRB timeout with error -110

Patches are included in 4.19-rc1

6e708000ec2c93c2bde6a46aa2d6c3e80d4eaeb9 - powerpc/powernv: Export opal_check_token symbol
656ecc16e8fc2ab44b3d70e3fcc197a7020d0ca5 - crypto/nx: Initialize 842 high and normal RxFIFO control registers

> Looks like the first commit was included in a recent 18.04 update
> (4.15.0-48.51), see
> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1819989
>
> but I don't see the second one there yet.
>
> If this is still needed, I would suggest getting this bug mirrored to LP to
> put on Canonical's radar.

We need second commit (656ecc16e8fc2ab44b3d70e3fcc197a7020d0ca) to fix this actual issue. But no use of having the first commit without second one. The first one just exports opal_check_token symbol which is used in the second commit.