Re: [RESEND PATCH 0/5] platform/x86: bitland-mifs-wmi: MIFS v2 firmware support (Xiaomi Book Pro 14 2026)

[Armin Wolf <W_Armin@gmx.de>]

Am 28.07.26 um 20:09 schrieb 孙 誉铭:

> Resending: the foxmail envelope rewrite (tencent...@qq.com) appears to
> have gotten the first attempt filtered. No content changes.
>
> This series makes the Bitland MIFS WMI driver work on the Xiaomi Book
> Pro 14 2026 (Intel Panther Lake, Ultra 5 358H) and very likely on the
> REDMI Book Pro 14 2025, whose suspend failure was reported earlier [1].
>
> These machines ship a reduced MIFS firmware ("v2"): the WMAA method
> implements only function groups 0x0800/0x0a00/0x0c00/0x1000, reports
> the performance mode as raw QFAN EC codes {2,3,4,9,10} instead of the
> v1 0..3 enumeration, and exposes no WMI fan function. Additionally the
> firmware never defines ECON, so \_SB.PC00.LPCB.Q_EC._STA fails and the
> ACPI EC driver never binds, which kills all EC query handlers
> (including the lid switch notifications _Q0C/_Q0D).

Sorry for the late reply.

This looks like a severe ACPI bug to me, can you share the output of "acpidump"?

Thanks,
Armin Wolf

> Symptoms fixed by this series, all reproduced and verified on the
> affected machine:
>
> * Suspend/hibernate aborted with -EINVAL from the driver's suspend
>    hook (same failure as [1]: "dpm_run_callback():
>    bitland_mifs_wmi_suspend returns -22"; 242 failures counted in
>    suspend_stats). Patch 1 makes the WMI call validate the firmware
>    status word and the suspend/resume hooks fault-tolerant.
>
> * power-profiles-daemon could not read or set the platform profile
>    ("Failed to get profile for handler bitland-mifs-wmi"; selecting
>    "performance" failed outright and wedged the daemon). Patch 2
>    detects the v2 firmware variant at probe and maps the QFAN codes
>    (2=quiet, 3=balanced, 4=speed, 9/10=extreme).
>
> * The hwmon device reported zero RPM on all channels because the v2
>    firmware has no WMI fan function. Patch 3 reads the two fan
>    tachometers (u16 RPM, 0 = stopped) from the EC shared-memory window
>    at 0xFE0B0300 (DSDT region "ERAM", offsets 0x69/0x6B).
>
> * Closing the lid produced no SW_LID event (screen stayed on, keys
>    pressed by the closed lid typed into the visible lock screen,
>    locking the account). Patch 4 polls the LSTE lid bit in the EC
>    window and, on a change, evaluates the very AML methods the EC
>    query would have run (_Q0C/_Q0D), restoring proper lid events.
>    DMI-gated to the affected model.
>
> All values were reverse-engineered from the machine's DSDT/SSDT
> (WMID device, _UID "MIFS") and verified live: mode switching changes
> the EC QFAN register as expected, fan tachs ramp 0 -> ~2700 RPM under
> load, lid close/open emit proper switch events consumed by
> systemd-logind, and suspend/resume cycles complete cleanly with the
> driver loaded (suspend_stats: fail 0).
>
> Notes for reviewers:
>
> * The v2 variant is detected at runtime (perf-mode query result
>    outside the v1 enumeration) so other Bitland machines sharing this
>    firmware generation get support without DMI entries; the lid quirk
>    additionally requires a DMI match.
> * On this platform the firmware perf-mode switch reaches Intel DTT
>    (\_SB.IETM, INTC10D4) via ODV variables; mainline has no driver for
>    that device, so the TDP change the firmware intends is currently
>    not applied on Linux. Programming RAPL directly from this driver
>    seemed inappropriate; I left it out. Happy to hear preferences.
> * Interactions with the in-flight "Merge redmi-wmi into
>    bitland-mifs-wmi" series [2] are limited to file context; the
>    control-device paths touched here are disjoint from the event-device
>    merge.
>
> [1] https://lists.openwall.net/linux-kernel/2026/07/10/72
>      "[BUG] platform/x86: bitland-mifs-wmi: Hibernation fails with
>      error -22 on Xiaomi Redmi Book Pro 14 2025"
> [2] https://www.spinics.net/lists/kernel/msg6309086.html
>      "[PATCH v1 0/4] Merge redmi-wmi into bitland-mifs-wmi"
>
>
> Yuming Sun (5):
>    platform/x86: bitland-mifs-wmi: validate WMAA status, never abort
>      suspend
>    platform/x86: bitland-mifs-wmi: support MIFS v2 perf-mode mapping
>    platform/x86: bitland-mifs-wmi: read fan tach from EC window on MIFS
>      v2
>    platform/x86: bitland-mifs-wmi: drive lid switch via EC poll on Xiaomi
>      Book Pro 14
>    Documentation: wmi: bitland-mifs-wmi: document MIFS v2 firmware
>      variant
>
>   .../wmi/devices/bitland-mifs-wmi.rst          |  26 ++
>   drivers/platform/x86/bitland-mifs-wmi.c       | 272 +++++++++++++++++-
>   2 files changed, 290 insertions(+), 8 deletions(-)
>