"Error parsing PCC subspaces from PCCT" during initializing the system

[Piotr Miszczak]

After an update such an error shows when I turn my xubuntu on.

I was wrinting on this also in https://bugs.launchpad.net/bugs/1528684

Thanks

[penalvch (penalvch)]

Piotr Miszczak, thank you for reporting this and helping make Ubuntu better.

In order to allow additional upstream developers to examine the issue, at your earliest convenience, could you please test the latest upstream kernel available from http://kernel.ubuntu.com/~kernel-ppa/mainline/?C=N;O=D ? Please keep in mind the following:
1) The one to test is at the very top line at the top of the page (not the daily folder).
2) The release names are irrelevant.
3) The folder time stamps aren't indicative of when the kernel actually was released upstream.
4) Install instructions are available at https://wiki.ubuntu.com/Kernel/MainlineBuilds .

If testing on your main install would be inconvenient, one may:
1) Install Ubuntu to a different partition and then test this there.
2) Backup, or clone the primary install.

If the latest kernel did not allow you to test to the issue (ex. you couldn't boot into the OS) please make a comment in your report about this, and continue to test the next most recent kernel version until you can test to the issue. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this issue is fixed in the mainline kernel, please add the following tags by clicking on the yellow circle with a black pencil icon, next to the word Tags, located at the bottom of the report description:
kernel-fixed-upstream
kernel-fixed-upstream-X.Y-rcZ

Where X, and Y are the first two numbers of the kernel version, and Z is the release candidate number if it exists.

If the mainline kernel does not fix the issue, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-X.Y-rcZ

Please note, an error to install the kernel does not fit the criteria of kernel-bug-exists-upstream.

Also, you don't need to apport-collect further unless specifically requested to do so.

Once testing of the latest upstream kernel is complete, please mark this report Status Confirmed. Please let us know your results.

Thank you for your understanding.

[Piotr Miszczak (pmiszcz)]

Sorry, but for some reason it doesn't want to accept it now, I'll try later.

This new kernel 4.5-rc7 loads the OS correctly I suppose, but does not fix the issue.
The same error still shows up. What's more, I think I glimpsed it while starting liveCD Xubuntu 15.10, but it works, I am currently using it.

[penalvch (penalvch)]

Piotr Miszczak, to clarify, did this issue not occur in a release prior to 15.10?

[Piotr Miszczak (pmiszcz)]

No. I was using at least 15.04 on this laptop for sure, that's the 1st problem of that kind. I think it occured tafter an update, but now it doesn't want to work also with older kernels. I had 15.10 for months and it was ok. Thanks

[Piotr Miszczak (pmiszcz)]

Sorry, yes - it didn't occur.

It was ok with 3.13.0-61, 3.19.0-31, after an update to 4.2.0-25 an error started to show up and now also older ones are not ok.
I also glimpsed this error while loading Xubuntu 15.10 liveCD, but it didn't crash and finally it was ok.

[penalvch (penalvch)]

Piotr Miszczak, to clarify, are you stating that the message is now occurring in kernels it previously did not show the message in (ex. 3.13.0-61 and 3.19.0-31)?

[Piotr Miszczak (pmiszcz)]

Yes, sorry if I am not precise enough. That's what I wanted to say. I thought that it was quite clear since the begging, sorry.

[penalvch (penalvch)]

Piotr Miszczak, no problem. This would indicate that this isn't a linux kernel issue. However, as the root cause hasn't been identified, I'll mark this Confirmed for now until the root cause has been identified, and this may be reassigned to the appropriate package.

[Piotr Miszczak (pmiszcz)]

Hi, I still have a problem, I've tried out new 4.6 kernel, but it doesn't help and couldn't make a bur report, so I've updated system on a standard kernel (4.2.0.36 or sth like that) and did it there - I'll attach it when I can, now I have no permission to the dist from CD-based system. In no way I can upgrade my system to Xubuntu 16.04. Any hints?

[Piotr Miszczak (pmiszcz)]

Christopher, here's sth
http://askubuntu.com/questions/702917/boot-into-emergency-mode-because-of-nouveau-error-parsing-pcc-subspaces-from-pc

I've no Windows on my laptop, but few kernels of linux -yes. Maybe there is a problem, hm?

[Christoph Weidemeyer (chriswe)]

Hello,
i face the same problem on my Thinkpad T450s.

I tested different Ubuntu versions with live-usb: Ubuntu 14.05, Ubuntu 16.04, Ubuntu 17.04, Linux Mint 18.2
The error always occurs on startup, with or without hdd. (BTW: I tried different USB drives)

On top of that i installed Windows 10 (Updates only available for Windows) and updated the BIOS of my t450s with no result. I tried different BIOS options (mentioned in many posts referred too this bug) like Legacy only, CSM Support on/off, secure boot deactivated, fast boot deactivated, ...

I try to install an Ubuntu only system, no dual boot. Does someone have any advice?

[Sujith Pandel (sujithpandel)]

CONFIG_MAILBOX and CONFIG_PCC are enabled.

I also checked the acpidump. The PCCT defines only a "Generic Communications Subspace" or Type-0 and not the other two types.
(Ref: http://elixir.free-electrons.com/linux/latest/source/include/acpi/actbl3.h#L481)

Whereas the acpi_pcc_probe takes count of only these 2 missing/not-defined PCC subspace types.. I do not know much about this to comment on why this approach..

(Ref: http://elixir.free-electrons.com/linux/latest/source/drivers/mailbox/pcc.c#L448)

Would like to have someone explain why kernel does not consider type-0 in this driver.