Uncategorized

Lenovo ACPI bug – affects X1C6, X1Y3, X280, T480s, T480, T580, P52s, possibly more. ‎

“This bug deserves more attention than it is currently receiving. It should be pinned in every forum with an affected machine, so that owners of those machines will be aware that it exists. It is currently squirreled away in the T series forum, under the outdated title “T480s – ACPI bug”. I have asked that the title be updated and received no response, which is why I’m posting this here.[…]

There’s a bug in the ACPI tables that affects all of the machines listed in the title. The bug causes heavy CPU usage on one thread due to frequent ACPI interrupts. The symptoms are a slow system, and high CPU temperatures (idles around 65 degrees Celsius). Some operating systems may mitigate the symptoms, but the bug is present regardless.

The following circumstances trigger it:
-powering on the laptop
-waking from suspend (and possibly hibernate – untested)

The following actions prevent it:
-reboot the laptop (temporary fix)
-disable thunderbolt in the UEFI settings (permanent fix – with latest UEFI updates)

The official UEFI update changelogs for all of these machines make explicit mention of this issue: “-(Fix) Fix an issue where system may become hot by system interrupts when Thundrebolt is disabled in ThinkPad Setup – Security – I/O Port Access.”[…]

https://forums.lenovo.com/t5/ThinkPad-X-Series-Laptops/ACPI-bug-affects-X1C6-X1Y3-X280-T480s-T480-T580-P52s-possibly/td-p/4084521

https://forums.lenovo.com/t5/ThinkPad-T400-T500-and-newer-T/T480s-ACPI-bug/m-p/4064963#M124889

https://forums.lenovo.com/t5/ThinkPad-T400-T500-and-newer-T/T480s-ACPI-bug/m-p/4067181#M124936

https://download.lenovo.com/pccbbs/mobiles/n22ur05w.txt

 

Standard

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

w

Connecting to %s