On 3/1/25 08:06, Antheas Kapenekakis wrote:
On Sat, 1 Mar 2025 at 14:52, Mario Limonciello <superm1@xxxxxxxxxx> wrote:
Let me know what you think!
I don't really like that profiles can get out of sync, this is asking
for a non-deterministic behavior that can be difficult to diagnose
issues and also difficult for userspace to work with.
I agree with Mario here. Imagine two drivers, one with low-power and
one with quiet. They both begin at performance.
Then, userspace software gets confused (incl. ppd) and sets firmware
profile to low-power. The latter gets left in performance, causing
excess drain.
I do not believe the legacy interface should be deprecated. Right now,
amd-pmf is a NOOP in most devices
"Most" devices is not accurate. There are a lot of devices that it does
enable. In the gaming space right now it's often behaving as a no-op.
That would be a fair description. Can you give some examples of
devices that use the interface? Devices with and without vendor
software.
Off hand the Framework 13 and 16 AMD both use PMF exclusively. So do a
bunch of HP commercial laptops.
Mark can keep me honest, but I want to say the Strix Thinkpad laptops
have both PMF and vendor interface (thinkpad-acpi).
>>
"Power mode" is a concept, it doesn't just apply to configuring sPPT and
fPPT. I envisage that a vendor that actively uses PMF and their own
interface would be changing different things by the different interfaces.
For "example" PMF may reconfigure sPPT, fPPT, STT and STAPM but their
driver may notify their EC to change a fan curve.
No. If PMF changes these values it also needs to change the fan curve
itself via the BIOS notification. Doing otherwise would lead to
situations where users do not install the vendor driver and cook their
device.
Fan curves are just that; curves. They just control how quickly fans
ramp up not whether or not they "work".
But in any case; that's a firmware issue not a platform profile design
issue.
So I expect that when PMF controls things it controls
everything. I would expect if vendors fallback to the pmf firmware
notifications while also providing vendor software there would be some
synergy between them, such as changing which fan preset is selected by
the PMF interface.
I can't control what vendors do; it's their decision how to manage their
systems. All I can do is provide infrastructure to help.
