Enable S3 sleep state for Elitebook 845G9

[cholez]

Hello there, here are some news on my investigation to get s2idle working on my 845g9.

I tried the latest BIOS from HP website (01.04.01, released the 14th February 2023) but it didn't help. The laptop still does not wake up from sleep but apparently this BIOS version solved the problem for a reddit user. So I am interested in feedback  from other users. To update the BIOS  without relying on windows I recommend to follow this convenient guide: https://blog.frehi.be/2022/05/04/updating-hp-bios-firmware-from-linux/

Anyway, I was actually able to better understand the problem and find a solution thanks to this post: https://gitlab.freedesktop.org/drm/amd/-/issues/2004

Apparently the BIOS of Elitebook 845G8 and G9 (but also probably 835, 855, 865 models) has an issue that prevents the laptop to resume from sleep when Drivelock is enabled (hardware full SSD encryption).

The solution that was found by Mario Limonciello and that is actually working for me is to use the kernel option iommu=pt but it exposes the laptop to DMA attacks, so it is not perfect for what should be a highly secure and professional laptop. This link explains how to add a kernel option in grub: https://wiki.ubuntu.com/Kernel/KernelBootParameters

Even if the laptop now resumes from sleep. The sleep drains the battery like hell. In 10 hours it emptied my battery. So it's not any better than doing nothing on the desktop.  So HP, please get back S3 mode in the next BIOS update!

Best regards,

[frank3431]

I use ubuntu 22.04 and battery drain like hell at sleep. We need S3 Sleep !!! 

[sjg103]

Nearly 2000 subscriptions to this thread. That's a lot of people who are wishing they had bought a ThinkPad instead of an EliteBook.

What we've all got is a laptop that won't last 12 hours away from mains power, unless we shut it down. How stupid is this?

Come on HP, a BIOS update to enable S3 sleep is absolutely required.

[sjg103]

For any frustrated Linux users arriving here, know that the S0ix support for AMD in Linux 6.2 is basically enough to alleviate the previously desperate need for S3 sleep state support. But you'll need to disable scatter/gather display functionally as per this. 

[cholez]

Hello,

Thanks for the information. Can you please elaborate a bit more on this? What got fixed in 6.2? What is the relationship with the display?

Thanks!

[sjg103]

https://www.phoronix.com/news/Linux-6.2-Rembrandt-Idle-Change

https://www.phoronix.com/news/AMD-Scatter-Gather-Re-Enabled