Re: [PATCH v5 0/7] platform/x86: lenovo-wmi-{capdata,other}: Add HWMON for fan speed

[Armin Wolf <W_Armin@gmx.de>]

Am 14.11.25 um 18:59 schrieb Rong Zhang:

> Lenovo WMI Other Mode interface also supports querying or setting fan
> speed RPM. This capability is decribed by LENOVO_CAPABILITY_DATA_00.
> Besides, LENOVO_FAN_TEST_DATA provides reference data for self-test of
> cooling fans, including minimum and maximum fan speed RPM.
>
> This patchset turns lenovo-wmi-capdata01 into a unified driver (now
> named lenovo-wmi-capdata) for LENOVO_CAPABILITY_DATA_{00,01} and
> LENOVO_FAN_TEST_DATA; then adds HWMON support for lenovo-wmi-other:
>
>   - fanX_enable: enable/disable the fan (tunable)
>   - fanX_input: current RPM
>   - fanX_max: maximum RPM
>   - fanX_min: minimum RPM
>   - fanX_target: target RPM (tunable)
>
> LENOVO_CAPABILITY_DATA_{00,01} presents on all devices, so
> both binds to lenovo-wmi-other. However, some device does not have
> LENOVO_FAN_TEST_DATA and its presence is described by
> LENOVO_CAPABILITY_DATA_00; hence, the former binds to the latter and a
> callback is used to pass the data to lenovo-wmi-other.
>
> The implementation does not rely on a specific binding sequence. This
> has been fuzz-tested using:
>
> 	#!/bin/bash
>
> 	DRV_DIR=/sys/bus/wmi/drivers/lenovo_wmi_cd
> 	CAPDATA_GUIDS=(
> 		$(find "$DRV_DIR"/ -name '*-*-*-*-*-*' -printf "%f ")
> 	)
>
> 	b() { sudo tee "$DRV_DIR"/bind <<<"$1"; }
> 	u() { sudo tee "$DRV_DIR"/unbind <<<"$1"; }
>
> 	for guid in "${CAPDATA_GUIDS[@]}"; do
> 		u "$guid"
> 	done
>
> 	while read -rsa perm; do
> 		for guid in "${perm[@]}"; do
> 			b "$guid"
> 		done
> 		sensors | grep -A3 lenovo_wmi_other || true
> 		for guid in "${perm[@]}"; do
> 			u "$guid"
> 		done
> 	done < <(python3 -c "
> 	from itertools import permutations
> 	ps = permutations('${CAPDATA_GUIDS[*]}'.split())
> 	for p in ps: print(' '.join(p))")
>
> 	for guid in "${CAPDATA_GUIDS[@]}"; do
> 		b "$guid"
> 	done
>
> Tested on ThinkBook 14 G7+ ASP.

Sorry for taking a bit to respond to your question regarding the previous
patch series. Your idea with the submaster seems good to me. Your script
for testing this is a very cool idea, are you OK with me adding  a
similar script to the tools/wmi/?

Thanks,
Armin Wolf

> Changes in v5:
> - Do not cast pointer to non-pointer or vice versa (thanks kernel test
>    robot)
> - Fix missing include (ditto)
> - Link to v4: https://lore.kernel.org/r/20251113191152.96076-1-i@rong.moe/
>
> Changes in v4:
> - Get rid of wmi_has_guid() (thanks Armin Wolf's inspiration)
>    - Add [PATCH v4 6/7], please review & test
>    - Rework HWMON registration
>      - Collect fan into from capdata00 and capdata_fan separately
>      - Use a callback to collect fan info from capdata_fan
>      - Trigger HWMON registration only if all fan info is collected
>      - Do not check 0x04050000.supported, implied by the presense of
>        capdata_fan
> - Drop Reviewed-by & Tested-by from [PATCH v4 7/7] due to the changes,
>    please review & test
> - Link to v3: https://lore.kernel.org/r/20251031155349.24693-1-i@rong.moe/
>
> Changes in v3:
> - Fix grammar (thanks Derek J. Clark)
> - Link to v2: https://lore.kernel.org/r/20251030193955.107148-1-i@rong.moe/
>
> Changes in v2:
> - Add a workaround for ACPI methods that return a 4B buffer for u32
>    (thanks Armin Wolf)
> - Fix function documentation (thanks kernel test bot)
> - Reword documentation (thanks Derek J. Clark)
> - Squash min/max reporting patch into the initial HWMON one (ditto)
> - Query 0x04050000 for interface availability (ditto)
>    - New parameter "expose_all_fans" to skip this check
> - Enforce min/max RPM constraint on set (ditto)
>    - New parameter "relax_fan_constraint" to disable this behavior
>    - Drop parameter "ignore_fan_cap", superseded by the next one
>    - New parameter "expose_all_fans" to expose fans w/o such data
> - Assume auto mode on probe (ditto)
> - Do not register HWMON device if no fan can be exposed
> - fanX_target: Return -EBUSY instead of raw target value when fan stops
> - Link to v1: https://lore.kernel.org/r/20251019210450.88830-1-i@rong.moe/
>
> Rong Zhang (7):
>    platform/x86: lenovo-wmi-helpers: Convert returned buffer into u32
>    platform/x86: Rename lenovo-wmi-capdata01 to lenovo-wmi-capdata
>    platform/x86: lenovo-wmi-{capdata,other}: Support multiple Capability
>      Data
>    platform/x86: lenovo-wmi-capdata: Add support for Capability Data 00
>    platform/x86: lenovo-wmi-capdata: Add support for Fan Test Data
>    platform/x86: lenovo-wmi-capdata: Wire up Fan Test Data
>    platform/x86: lenovo-wmi-other: Add HWMON for fan reporting/tuning
>
>   .../wmi/devices/lenovo-wmi-other.rst          |  43 +-
>   drivers/platform/x86/lenovo/Kconfig           |   5 +-
>   drivers/platform/x86/lenovo/Makefile          |   2 +-
>   drivers/platform/x86/lenovo/wmi-capdata.c     | 808 ++++++++++++++++++
>   drivers/platform/x86/lenovo/wmi-capdata.h     |  65 ++
>   drivers/platform/x86/lenovo/wmi-capdata01.c   | 302 -------
>   drivers/platform/x86/lenovo/wmi-capdata01.h   |  25 -
>   drivers/platform/x86/lenovo/wmi-helpers.c     |  22 +-
>   drivers/platform/x86/lenovo/wmi-other.c       | 511 ++++++++++-
>   9 files changed, 1426 insertions(+), 357 deletions(-)
>   create mode 100644 drivers/platform/x86/lenovo/wmi-capdata.c
>   create mode 100644 drivers/platform/x86/lenovo/wmi-capdata.h
>   delete mode 100644 drivers/platform/x86/lenovo/wmi-capdata01.c
>   delete mode 100644 drivers/platform/x86/lenovo/wmi-capdata01.h
>
>
> base-commit: 6da43bbeb6918164f7287269881a5f861ae09d7e