Created attachment 256825 [details]
early boot log with kernel 4.11.2
My machine boots fine with kernel 4.11.3. However, on the next boot, the firmware says: "Configuration Changed - Requires restart", and the firmware settings are reset to defaults. There was no such issue with the 4.10 kernels.
My machine is a Lenovo Thinkpad Yoga (first generation) with the latest firmware revision.
I attach a piece of logs I gathered booting kernel 4.11.2 with efi=debug. Is there any other piece of data I can provide?
I can confirm this bug on the same hardware for all current kernel versions from 4.11 on. I tested on Fedora:
All of them suffer from the issue, while 4.10 does not.
*** Bug 195975 has been marked as a duplicate of this bug. ***
Could you try doing a git bisect to track down which commit introduced the issue? I looked at the EFI changes between v4.10 and v4.11 but nothing obvious stood out.
I bisected the issue to commit ff00d7a32a1b88b772981a13fc198e0d29300666: "mfd: lpc_ich: Add support for SPI serial flash host controller".
Thanks for bisecting. Re-assigning since this doesn't look like an EFI issue per se.
Mika, can you take a look?
Can you attach full dmesg to the bug and then revert ff00d7a32a1b88b772981a13fc198e0d29300666 and attach dmesg of that boot as well?
Created attachment 257711 [details]
dmesg log at 8afda8b2 (good)
Created attachment 257713 [details]
dmesg log at ff00d7a3 (bad)
I attached the logs you requested. The git hashes in the logs do not match the hash in the kernel version because in order to work-around a gcc7 build problem I cherry-picked 474c9015 on top.
Both logs say kernel v4.10 is that expected?
Yes, this is what git-describe reports. The bug was introduced in the 4.11 merge windows, so git describe reports 4.10-blah-blah.
Created attachment 257715 [details]
Prevent touching BCR register from lpc_ich.c
Can you try the attached patch and see if it makes a difference?
Yes, it does. With your patch on top of the bad commit, the problem disappears.
OK, thanks for testing. I'll prepare proper patch and send it upstream tomorrow.
I upgraded Ubuntu on my thinkpad yoga machine (1st gen) from 17.04 (kernel 4.10) to 17.10 (kernel 4.13) and this issue is introduced. I also tried Fedora 26 (kernel 4.11) live cd, and noticed the same problem.
Hi Mika, this bug also affects me. Has your patch been committed?
Yes, it should be included in v4.14-rc1+