From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A669C286410 for ; Sat, 14 Mar 2026 12:57:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773493062; cv=none; b=pz3mTm0XEeOMuFGZRG+otDO5mHnmGUkHkOqqgbJOyNvHVeN163m/MThq5kzZVIaMV+aQYmm79c6sXLbUZhDNcgQLjK8zFDvzosz0K7aJksdmKti4UM7xhyIhjcL6C2oFk+UCk/1mSSNcc3n4Z4j9yc6qaP0HDKfoU37Vcqjdh04= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773493062; c=relaxed/simple; bh=0/jA4H03GGn6R0nuYoVTIkife+6XYViCeRF0j8slkpk=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=lXltW9xNyfFQo+yPU3ius/Ew/uL/C3DKw/vKz2Y7Wo86rPtpB0+Fclhf3SNImVeOWaTtdPHlPyZXO7et++k6iwX8XAxX+0Qg9OZkyeuMaX8bcBVF//FnNJW45G/C/DE4J3BZtpF/3K7wXewXeDliIqEGhDXS/zeKrAg9cKZwM7E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fMgpqlGe; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fMgpqlGe" Received: by smtp.kernel.org (Postfix) with ESMTPS id 3A57DC19425 for ; Sat, 14 Mar 2026 12:57:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773493062; bh=0/jA4H03GGn6R0nuYoVTIkife+6XYViCeRF0j8slkpk=; h=From:To:Subject:Date:In-Reply-To:References:From; b=fMgpqlGeKJYsJE/xrRBNxVHpky/NctILrVUSZGHZ7ZZEwG5fsxcjMfRVQIW2a1Qek XWD1+8wx+hKlquM+cUu63EJ4ZpGBDc8ZjdzECTNQNhw+oRp+uyc2lPgSRqKZ2D4ty2 u6/zzFPvgqvlubI3C/4i/gPkHztKDHp8hHMM6kkOOA5PFQQ1WY5lUMVgdLNHiMaeWB yNhAj0sxke+4biahcNjBzmzz0SvRy4OTBlsLAteYIzuERBZMrrb5jTebAVgQW7/bdf B6ytxnj58KUGEG52Bn9hHi5Klkvle3B6l4WmaFhdZ3CSjuVCFakYWzVni+CN2c6360 IVqCO5D38gosg== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id 3467DC41612; Sat, 14 Mar 2026 12:57:42 +0000 (UTC) From: bugzilla-daemon@kernel.org To: platform-driver-x86@vger.kernel.org Subject: [Bug 204807] Hardware monitoring sensor nct6798d doesn't work unless acpi_enforce_resources=lax is enabled Date: Sat, 14 Mar 2026 12:57:39 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: AssignedTo drivers_platform_x86@kernel-bugs.osdl.org X-Bugzilla-Product: Drivers X-Bugzilla-Component: Platform_x86 X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: high X-Bugzilla-Who: ptscheepers@gmail.com X-Bugzilla-Status: RESOLVED X-Bugzilla-Resolution: CODE_FIX X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: drivers_platform_x86@kernel-bugs.osdl.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated Precedence: bulk X-Mailing-List: platform-driver-x86@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 https://bugzilla.kernel.org/show_bug.cgi?id=3D204807 Theunis Scheepers (ptscheepers@gmail.com) changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |ptscheepers@gmail.com --- Comment #351 from Theunis Scheepers (ptscheepers@gmail.com) --- Requesting addition of ROG STRIX X870E-E GAMING WIFI to the nct6775-platfor= m.c ASUS WMI board allowlist for stable fan PWM control under Linux. BACKGROUND ---------- The asus-ec-sensors driver already supports this board for temperature read= ings (CPU, CPU Package, Motherboard, VRM) and the CPU_Opt fan tachometer. Howeve= r, persistent fan speed control via PWM is not possible because the board is missing from the nct6775 WMI platform allowlist. The nct6799 Super-I/O chip (NCT6796D-S/NCT6799D-R) is detected at 0x2e:0x290 and exposes pwm1-pwm7 via direct ISA access through the nct6775 driver. Wri= ting PWM values via ISA succeeds momentarily, but the ASUS EC/ACPI firmware does= not cooperate with direct ISA writes and overrides the control mode within seco= nds. The board needs the WMI cooperative path for stable fan control. PWM OVERRIDE TEST (ISA writes don't persist) --------------------------------------------- I tested writing to pwm2 (which controls fan2, the only case fan currently connected to the nct6799 channels): Before: fan2=3D473 RPM, pwm2_enable=3D5, pwm2=3D82 (set pwm2_enable=3D1, pwm2=3D255) After 1s: fan2=3D474 RPM, pwm2_enable=3D0, pwm2=3D255 After 6s: fan2=3D1433 RPM, pwm2_enable=3D0, pwm2=3D255 After 11s: fan2=3D1470 RPM, pwm2_enable=3D0, pwm2=3D255 Restored pwm2_enable to 5 (BIOS Q-Fan) The firmware immediately changed pwm2_enable from 1 (manual) to 0 (full spe= ed) rather than respecting the manual control mode. The fan did ramp up because= the PWM duty was set to 255, but the control mode was overridden. This confirms= the hardware supports PWM control but requires the WMI path to cooperate with t= he ASUS firmware rather than fighting it via direct ISA writes. All seven PWM channels default to pwm_enable=3D5 (SmartFan/BIOS-controlled): fan1: 0 RPM, pwm1_enable: 5, pwm1: 255 fan2: 473 RPM, pwm2_enable: 5, pwm2: 82 fan3: 0 RPM, pwm3_enable: 5, pwm3: 255 fan4: 0 RPM, pwm4_enable: 5, pwm4: 255 fan5: 543 RPM, pwm5_enable: 5, pwm5: 86 fan6: 0 RPM, pwm6_enable: 5, pwm6: 255 fan7: 0 RPM, pwm7_enable: 5, pwm7: 210 RELATION TO X870E-H ------------------- The closely related ROG STRIX X870E-H GAMING WIFI7 was recently added to the allowlist. The patch description notes it "has a similar sensor configurati= on as the ROG STRIX X870E-E GAMING WIFI", so adding the X870E-E variant should= be straightforward. DSDT WMI METHODS ---------------- The decompiled DSDT confirms the WMI interface is present: WMBD (WMI method dispatch) at line 8377 BREC (read EC) at line 9261 BWEC (write EC) at line 9267 \_SB.PCI0.SBRG.SIO1 (Super-I/O device) referenced throughout SYSTEM INFO ----------- Board: ASUSTeK COMPUTER INC. ROG STRIX X870E-E GAMING WIFI (Rev 1.xx) BIOS: 2004 Kernel: 6.19.6-2-cachyos (x86_64, CachyOS/Arch) Super-I/O: NCT6796D-S/NCT6799D-R at 0x2e:0x290 CPU: AMD Ryzen 7 9800X3D Loaded hwmon-related modules: asus_ec_sensors - provides CPU, CPU Package, Motherboard, VRM temps and CPU_Opt fan asus_wmi (via eeepc_wmi) nct6775 + nct6775_core - ISA access to nct6799, detects fans and PWM but = no stable write path k10temp - CPU thermal amdgpu - GPU thermal No ACPI resource conflicts were found in dmesg. COLLECTED DATA -------------- 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 USE CASE -------- I want to run GPU-temperature-driven case fan curves via CoolerControl, whi= ch requires stable writable PWM interfaces. The nct6799 PWM channels are the o= nly path to the motherboard fan headers, and they need the WMI allowlist entry = to work reliably without firmware conflict. Happy to test patches. Thanks. --=20 You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.=