On Fri, May 16, 2025 at 3:59 PM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote: > > On Sat, May 3, 2025 at 12:29 AM Armin Wolf <W_Armin@xxxxxx> wrote: > > > > Am 28.04.25 um 14:34 schrieb Rafael J. Wysocki: > > > > > On Mon, Apr 28, 2025 at 2:31 PM Armin Wolf <W_Armin@xxxxxx> wrote: > > >> Am 27.04.25 um 00:52 schrieb Armin Wolf: > > >> > > >>> Am 26.04.25 um 15:12 schrieb Rafael J. Wysocki: > > >>> > > >>>> On Sat, Apr 26, 2025 at 1:20 AM Armin Wolf <W_Armin@xxxxxx> wrote: > > >>>>> Am 10.04.25 um 18:54 schrieb Armin Wolf: > > >>>>> > > >>>>>> The ACPI specification defines an interface for the operating system > > >>>>>> to change the preferred cooling mode of a given ACPI thermal zone. > > >>>>>> This interface takes the form of a special ACPI control method called > > >>>>>> _SCP (see section 11.4.13 for details) and is already supported by the > > >>>>>> ACPI thermal driver. > > >>>>>> > > >>>>>> However this support as many issues: > > >>>>>> > > >>>>>> - the kernel advertises support for the "3.0 _SCP Extensions" > > >>>>>> yet the > > >>>>>> ACPI thermal driver does not support those extensions. This may > > >>>>>> confuse the ACPI firmware. > > >>>>>> > > >>>>>> - the execution of the _SCP control method happens after the driver > > >>>>>> retrieved the trip point values. This conflicts with the ACPI > > >>>>>> specification: > > >>>>>> > > >>>>>> "OSPM will automatically evaluate _ACx and _PSV objects after > > >>>>>> executing _SCP." > > >>>>>> > > >>>>>> - the cooling mode is hardcoded to active cooling and cannot be > > >>>>>> changed by the user. > > >>>>>> > > >>>>>> Those issues are fixed in this patch series. In the end the user > > >>>>>> will be able to tell the ACPI firmware wether he prefers active or > > >>>>>> passive cooling. This setting will also be interesting for > > >>>>>> applications like TLP (https://linrunner.de/tlp/index.html). > > >>>>>> > > >>>>>> The whole series was tested on various devices supporting the _SCP > > >>>>>> control method and on a device without the _SCP control method and > > >>>>>> appears to work flawlessly. > > >>>>> Any updates on this? I can proof that the new interface for setting > > >>>>> the cooling mode > > >>>>> works. Additionally the first two patches fix two issues inside the > > >>>>> underlying code > > >>>>> itself, so having them inside the mainline tree would be beneficial > > >>>>> to users. > > >>>> Sure. > > >>>> > > >>>> I'm going to get to them next week, probably on Monday. > > >>> Ok, thanks. > > >>> > > >>> Armin Wolf > > >>> > > >> I am a bit ashamed of myself but i think we need to put this patch series on hold after all :(. > > >> > > >> The reason of this is that i am confused by the ACPI specification regarding _SCP: > > >> > > >> 11.1.2.1. OSPM Change of Cooling Policy > > >> > > >> When OSPM changes the platform’s cooling policy from one cooling mode to the other, the following occurs: > > >> > > >> 1. OSPM notifies the platform of the new cooling mode by running the Set Cooling Policy (_SCP) control method in all thermal zones and invoking the OS-specific Set Cooling Policy interface to all participating devices in each thermal zone. > > >> > > >> 2. Thresholds are updated in the hardware and OSPM is notified of the change. > > >> > > >> 3. OSPM re-evaluates the active and passive cooling temperature trip points for the zone and all devices in the zone to obtain the new temperature thresholds. > > >> > > >> This section of the ACPI specification tells me that we need to evaluate the _SCP control method of all ACPI thermal zones > > >> at the same time, yet section 11.4.13. tells me that each _SCP control methods belongs to the individual thermal zone. It just says "This object may exist under a thermal zone or a device" so I don't see any contradiction. Section 11.4.13 says where it is located and Section 11.1.2.1 says when to evaluate it. However, Section 11.4.13 also says "OSPM will automatically evaluate _ACx and _PSV objects after executing _SCP" which is not arranged for in your patch [3/3] IIUC. Thanks!
