[Bug 204807] Hardware monitoring sensor nct6798d doesn't work unless acpi_enforce_resources=lax is enabled

bugzilla-daemon
2026-03-14T23:41:53Z

--- Comment #353 from Theunis Scheepers (ptscheepers@gmail.com) ---
(In reply to Denis Pauk from comment #352)
> (In reply to Theunis Scheepers from comment #351)
> > Requesting addition of ROG STRIX X870E-E GAMING WIFI to the
> > nct6775-platform.c ASUS WMI board allowlist for stable fan PWM control
> under
> > Linux.
> > --------------
> > A full data tarball (DSDT binary + decompiled, sensors-detect, dmesg, PWM
> > override test, hwmon drivers list) is attached to:
> > https://github.com/zeule/asus-ec-sensors/issues/100
>
> The dmesg log attached to github issue does not have mention about resource
> conflict or applying some custom parameters/patches.
>
> Have you applied some patches or custom parameters for the kenel? Could you
> please provide dmesg messages before and after applying patch or custom
> parameter?
>
> Use comment #350 as example of patch.

Hi Denis,
Testing results for ROG STRIX X870E-E GAMING WIFI.
System Info:

Board: ROG STRIX X870E-E GAMING WIFI (DMI vendor: ASUSTeK COMPUTER INC.)
Kernel: 6.19.8-1-cachyos (CachyOS, Arch-based)
Chip: NCT6796D-S/NCT6799D-R

Key Finding:
This board needs to go in asus_msi_boards[], NOT asus_wmi_boards[]. The ACPI
WMI device has UID AsusMbSwInterface (not ASUSWMI), so asus_wmi_boards[] does
not match.
BEFORE patch (ISA path):

dmesg: Found NCT6796D-S/NCT6799D-R or compatible chip at 0x2e:0x290
No WMI mention in dmesg
PWM writes via ISA held intermittently but firmware can override

AFTER patch (WMI path via asus_msi_boards[]):

dmesg: Using Asus WMBD method of AsusMbSwInterface to access 0xc1 chip
WMI read confirmed: ret=0 tmp=0xc1
PWM writes persist for 22+ seconds
Fan RPM responds correctly: 1468 → 1153 RPM when setting PWM to 200
Firmware does NOT override manual control

The patch (one line added to asus_msi_boards[] in nct6775-platform.c):
"ROG STRIX X670E-I GAMING WIFI",
+ "ROG STRIX X870E-E GAMING WIFI",
"ROG STRIX X870E-H GAMING WIFI7",
Full before/after dmesg logs and PWM test results attached if needed.