AMD S2idle Support For Linux Getting Squared Away

[phoronix]

Phoronix: AMD S2idle Support For Linux Getting Squared Away

Just in time for the upcoming AMD Ryzen 5000 series mobile processors, it's looking like the S2idle support is finally coming together on Linux for increased power savings...

http://www.phoronix.com/scan.php?page=news_item&px=AMD-S2idle-ACPI-Linux-5.11

[Guest]

Cool, but which CPUs does this support? Server CPUs only? Or only those specific mobile CPUs that will be used in Chromebooks? And are those the same CPU models that will be used in non-Chromebook laptops as well?

[EarthMind]

It's kind of funny to see AMD take advantage of code written by their competitor

[r1348]

It's kind of funny to see AMD take advantage of code written by their competitor

It's quite normal and even expected in open source code development.

[torsionbar28]

It's kind of funny to see AMD take advantage of code written by their competitor

You mean just like Intel using the AMD64 instruction set instead of their own failed attempt at 64 bit, the Itanium?

[tajjada]

You mean, *reduced* power savings.

I hate this new trend of laptops removing support for the traditional S3 suspend state (which properly powers down the entire platform except for RAM) and only supporting S0ix (s2idle) (which is basically the entire system still powered on, but with the CPU in a deep idle state). They say it is to allow for "a device instant-on experience" and getting email notifications and such in the background, like on a phone. I get that Microsoft really wants to be able to have background network activity even while the system is sleeping, but this is *not* an improvement in user experience, no matter how they try to spin it.

My current laptop (Dell XPS 2-in-1 with 10gen intel icelake) is one of these devices with no proper suspend/S3 support. I have mostly switched to using hibernation instead of suspend, because, simply put, I don't know if it will still have battery when I come back and want to use it. All of my older laptops used to be able to stay in a suspended state for days and still have battery, never had to worry about it. With this laptop, if I leave it suspended overnight (or through the day) and not plugged into a charger, when I come back to use it, I'd probably find it low on battery or dead.

Ironically, the "feature" they've been promoting for "instant-on resume experience" made my laptop unusable in that way and pushed me to use hibernation, which has slower resume times than the old S3 suspend and wears my SSD. But it is the only way to not worry about battery charge all the time.

Honestly, with the fast NVMe SSDs nowadays and fast boot settings, hibernate and resume from hibernation are pretty fast (~6-7 sec from power button press until I am in the desktop). But it's still a shame that I have to do this instead of suspend.

Most new laptops are allegedly like my current laptop with their support (or lack thereof) for suspend states. It seems to be something that Microsoft and Intel are pushing, because I've heard some laptop brands that sell models with Linux preinstalled come with proper firmware supporting S3 suspend, while those that come with Windows don't. It's a shame and I'm sad to hear that AMD is also going in this direction.

/rant

[agd5f]

Cool, but which CPUs does this support? Server CPUs only? Or only those specific mobile CPUs that will be used in Chromebooks? And are those the same CPU models that will be used in non-Chromebook laptops as well?

Client parts (e.g., APUs in laptops). Servers generally don't support modern standby. It's only required if your device does not support legacy S3 (e.g., modern standby only systems).

[Guest]

You mean, *reduced* power savings.

I hate this new trend of laptops removing support for the traditional S3 suspend state (which properly powers down the entire platform except for RAM) and only supporting S0ix (s2idle) (which is basically the entire system still powered on, but with the CPU in a deep idle state). They say it is to allow for "a device instant-on experience" and getting email notifications and such in the background, like on a phone. I get that Microsoft really wants to be able to have background network activity even while the system is sleeping, but this is *not* an improvement in user experience, no matter how they try to spin it.

My current laptop (Dell XPS 2-in-1 with 10gen intel icelake) is one of these devices with no proper suspend/S3 support. I have mostly switched to using hibernation instead of suspend, because, simply put, I don't know if it will still have battery when I come back and want to use it. All of my older laptops used to be able to stay in a suspended state for days and still have battery, never had to worry about it. With this laptop, if I leave it suspended overnight (or through the day) and not plugged into a charger, when I come back to use it, I'd probably find it low on battery or dead.

Ironically, the "feature" they've been promoting for "instant-on resume experience" made my laptop unusable in that way and pushed me to use hibernation, which has slower resume times than the old S3 suspend and wears my SSD. But it is the only way to not worry about battery charge all the time.

Honestly, with the fast NVMe SSDs nowadays and fast boot settings, hibernate and resume from hibernation are pretty fast (~6-7 sec from power button press until I am in the desktop). But it's still a shame that I have to do this instead of suspend.

Most new laptops are allegedly like my current laptop with their support (or lack thereof) for suspend states. It seems to be something that Microsoft and Intel are pushing, because I've heard some laptop brands that sell models with Linux preinstalled come with proper firmware supporting S3 suspend, while those that come with Windows don't. It's a shame and I'm sad to hear that AMD is also going in this direction.

/rant

Well it's because Windows is trying to adapt and be like Android/iOS - check for instant notifications like messages, email, SMS etc. This is more useful for tablet computers like the Surface, which is trying to compete with iPads, Android tablets (including Kindle tablets).

[polarathene]

All of my older laptops used to be able to stay in a suspended state for days and still have battery, never had to worry about it. With this laptop, if I leave it suspended overnight (or through the day) and not plugged into a charger, when I come back to use it, I'd probably find it low on battery or dead.

Ironically, the "feature" they've been promoting for "instant-on resume experience" made my laptop unusable in that way and pushed me to use hibernation, which has slower resume times than the old S3 suspend and wears my SSD. But it is the only way to not worry about battery charge all the time.

Mine is CometLake, I'm not sure if it properly supports s2idle, S3 was an issue as it'd kernel panic on the 2nd resume from suspend since boot, but there's a firmware update that fixes that (requires re-installing windows to apply however..).

I tried to use s2idle, but because my laptop is a budget model, despite being from a 2019Q4 product release, it had a 2017 manufactured display panel with 2011 eDP version whatever that lacked Panel-Self-Refresh(PSR) support. That prevents the iGPU entering deeper power states, which prevents the system entering lower power states too, thus power usage doesn't seem to drop that much as it's probably intended to. Thus like you, I found battery life not really lasting a day in that "power saving state". On the plus side it didn't cause kernel panics.

I ended up going with hibernation as well, also with an NVMe disk so the delay is minimal. It would seem unlikely that your Dell laptop would have skimped on the display panel technology though, so I wonder why it's struggling with s2idle as well. Did it come with Linux or Windows pre-installed? I've heard that ACPI tables or something related to that can be a problem with linux support regarding the feature (lot of effort on that front with Microsoft Surface tablets open-source contributors enabling proper s2idle with Linux via patches).

[arQon]

You mean, *reduced* power savings.

Yeah, the whole concept is garbage. WiFi is one of the biggest power consumers on a laptop, and as you say, the whole @#$%ing POINT of suspend is that it powers everything down to, yknow, save power. I really don't want the 200GB+/day of writes to an SSD that hibernation causes as the only way to work around this sort of stupidity.

Maybe rfkill can help enough to be a workable way to deal with things, but I'd much rather just have proper suspend in the first place.