From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=185.70.43.22 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793348433; b=KFeUPxAxqF/2FsFG8ebfg+UwWSIq3V52kMDeGyp2nZmvwRrPX7zBAv95LCmBV9Xp3r3x U5Z2InnQQZ5YSKExBmtE/YqW2bRFk40sOyhBLFhvH0OwZOjaKv21YPKVVCcrV3stlpgJG ISzbfeRUVSSnJlf22lV9qLnuvwA7bISSxokwbfiuFv7YocYLeOwdUP2F67cN2LhK7SpJc USA+MR6CXyzU+gmmETF0Omc3TyZTHJBe3hUv0xJe0RSMf/TnegjlN1FmLbUED2jeEkCfM lZInbBMnmkA7cDMfWKZnF1ZtbOOCsZj2tvBYLh0IM0ys58+rtGAA1D8HmGc+cPvynlA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793348433; h=DMARC-Filter:DKIM-Signature:Date:To:From:Cc:Subject:Message-ID: In-Reply-To:References:Feedback-ID:X-Pm-Message-ID:MIME-Version: Content-Type; bh=eMw0Tsc5hY6DqmDs0szKnY0CQ5h9hvbZXBJZty/2/ZY=; b=MMkOchM3/1CjcUemjJ5jQl77UrO/q/Vozvnwp9zPi8eC7R+Y3lK++B8rkTKnbe0hrRMv V6Lk/gVzamXmAgPqw8p0YnFI8bFQQCLa013tAlipf54uq15zb+22SHBhRnS7rpIJKpXyi XpO38q15IXZYyVFd79z4gAG7UMocF/gz+y6mKZmh63KAu+vD4/s8MJBY79xvmXJrTPKEt +gFWXquSskuePOaEpfbRvqlagm+XAZMUu2br5a7Sls3ruTdHVT4eJJcgTPjIjCrfpOg7w dJ5LqfO5gKvK1Qyz4stRX9+YUVcQAn+0DENZKK33GnqDE4qB3wKDWWeK08h7PWYjujA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=proton.me; spf=pass smtp.mailfrom=proton.me; dkim=pass header.d=proton.me header.i=@proton.me header.a=rsa-sha256 header.s=protonmail2 header.b=aTFFpxxh; arc=none smtp.remote-ip=185.70.43.22 Received: from mail-4322.protonmail.ch (mail-4322.protonmail.ch [185.70.43.22]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 77DBD606A333 for ; Fri, 30 Oct 2026 08:20:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 77DBD606A333 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=proton.me Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=proton.me Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=proton.me header.i=@proton.me header.a=rsa-sha256 header.s=protonmail2 header.b=aTFFpxxh DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=proton.me; s=protonmail2; t=1793348430; x=1793607630; bh=eMw0Tsc5hY6DqmDs0szKnY0CQ5h9hvbZXBJZty/2/ZY=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID:BIMI-Selector; b=aTFFpxxhvkz0apQitjCI++GPp1sNBCa5jWnWyXYFtz1GKCM+9ohYEg83HdgIiZiff 0KvYohZZJ9NHir8hk7O1KmwAnaLp42qpwZ10UltJy9alQ3bdCBl3+ERqdUmp0dAIZk MXgrUAgXOIIBmtcYsP4k+OjmPARdPdipTAXBtiebXQ2v+570qUTCUMhSZTUz7UlG06 pLZ4qyavffn3G22B3YniS687Nc60WSfa6Mzy4a2fwEACWyaCllKftcsC5q1qAEcubD UFVvaDw+7uNwzf3qnnS+QhB79cv3773dTfsOm83etzYEyQaEnxRxFK8EJ0IalDVIxv EQDh7PRa+bNyQ== Date: Fri, 30 Oct 2026 08:20:25 +0000 To: linux-i2c@vger.kernel.org From: Yazoudi Cc: linux-kernel@vger.kernel.org Subject: [Linux I2C/SMBus] AMD FCH SMBus controller fails to bind on Gigabyte B850M FORCE WIFI6E Message-ID: <70db7519-da14-4b59-a196-27f5b67c84bd@proton.me> In-Reply-To: References: Feedback-ID: 197040310:user:proton X-Pm-Message-ID: f6cb6cce089e0a0c6e4fed18b1de0a903a89c4c0 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="b1=_tas4pBrJGPaOHPqnjwdzTAuh5bgQkqaAUyBar8YW1vc" --b1=_tas4pBrJGPaOHPqnjwdzTAuh5bgQkqaAUyBar8YW1vc Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Hello, I am investigating an SMBus controller that does not bind to the Linux=20 i2c_piix4 driver on my Gigabyte B850M FORCE WIFI6E (revision 1.0)=20 motherboard. The PCI device is detected, and i2c_piix4 is listed as a candidate=20 module, but no driver is bound to the device. The kernel also logs an=20 ACPI resource conflict involving the SMBus I/O range and the GSA1.SMBI=20 operation region. System details: * Motherboard: Gigabyte B850M FORCE WIFI6E, revision 1.0 * BIOS: F8a * Distribution: Arch Linux with zen kernel * Kernel: 7.2.11-zen1-1-zen * SMBus PCI device: 00:14.0, AMD FCH SMBus Controller [1022:790b], revision 71 * PCI subsystem: Gigabyte [1458:5001] Relevant observations: 1. |lspci -nnk -s 00:14.0|lists |i2c_piix4|under Kernel modules, but does not show a Kernel driver in use. 2. |/sys/bus/pci/devices/0000:00:14.0/driver|does not resolve to a driver. 3. The kernel logs: |ACPI Warning: SystemIO range 0x0000000000000B00-0x0000000000000B08 conflicts with OpRegion 0x0000000000000B00-0x0000000000000B0F (\GSA1.SMBI)| followed by: |ACPI: OSL: Resource conflict; ACPI support missing from driver?| 4. |/proc/ioports|lists |0b00-0b0f : PNP0C02:03|. 5. Reloading i2c_piix4 does not bind the driver, and no SMBus adapter appears among the available I=C2=B2C adapters. I originally investigated this because OpenRGB cannot detect my KLEVV=20 CRAS V RGB DDR5 modules. The |spd5118|driver loads, but no SPD devices=20 are instantiated. I understand that SPD access and RGB control are=20 separate issues; my immediate concern is the SMBus controller not binding. I found a related patch discussion concerning an ACPI resource conflict=20 on the Gigabyte X870 EAGLE WIFI7: https://lkml.rescloud.iu.edu/2608.1/09152.html=20 That is a different motherboard, so I do not know whether the same=20 underlying issue applies here. Could you advise whether this looks like an ACPI resource reservation=20 preventing i2c_piix4 from binding, and what additional diagnostics would=20 help establish the cause? I have not forced the driver to bind or=20 disabled the kernel's ACPI resource protections. I can provide the full kernel log, PCI configuration, and other=20 diagnostic output if needed. Thank you. --b1=_tas4pBrJGPaOHPqnjwdzTAuh5bgQkqaAUyBar8YW1vc Content-Type: text/plain; charset=UTF-8; name=diagnostics.txt Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename=diagnostics.txt PT09IEtlcm5lbCA9PT0KTGludXggWWF6b3VkaVBjIDcuMi4xMS16ZW4xLTEtemVuICMxIFpFTiBT TVAgUFJFRU1QVF9EWU5BTUlDIEZyaSwgMTYgT2N0IDIwMjYgMDA6Mjg6NDIgKzAwMDAgeDg2XzY0 IEdOVS9MaW51eApMaW51eCB2ZXJzaW9uIDcuMi4xMS16ZW4xLTEtemVuIChsaW51eC16ZW5AYXJj aGxpbnV4KSAoZ2NjIChHQ0MpIDE2LjIuMSAyMDI2MDgxMCwgR05VIGxkIChHTlUgQmludXRpbHMp IDIuNDcpICMxIFpFTiBTTVAgUFJFRU1QVF9EWU5BTUlDIEZyaSwgMTYgT2N0IDIwMjYgMDA6Mjg6 NDIgKzAwMDAKCj09PSBEaXN0cmlidXRpb24gPT09Ck5BTUU9IkFyY2ggTGludXgiClBSRVRUWV9O QU1FPSJBcmNoIExpbnV4IgpJRD1hcmNoCkJVSUxEX0lEPXJvbGxpbmcKQU5TSV9DT0xPUj0iMzg7 MjsyMzsxNDc7MjA5IgpIT01FX1VSTD0iaHR0cHM6Ly9hcmNobGludXgub3JnLyIKRE9DVU1FTlRB VElPTl9VUkw9Imh0dHBzOi8vd2lraS5hcmNobGludXgub3JnLyIKU1VQUE9SVF9VUkw9Imh0dHBz Oi8vYmJzLmFyY2hsaW51eC5vcmcvIgpCVUdfUkVQT1JUX1VSTD0iaHR0cHM6Ly9naXRsYWIuYXJj aGxpbnV4Lm9yZy9ncm91cHMvYXJjaGxpbnV4Ly0vaXNzdWVzIgpQUklWQUNZX1BPTElDWV9VUkw9 Imh0dHBzOi8vdGVybXMuYXJjaGxpbnV4Lm9yZy9kb2NzL3ByaXZhY3ktcG9saWN5LyIKTE9HTz1h cmNobGludXgtbG9nbwoKPT09IE1vdGhlcmJvYXJkIGFuZCBCSU9TID09PQpCODUwTSBGT1JDRSBX SUZJNkUKeC54CkY4YQowMy8xMS8yMDI2Cgo9PT0gU01CdXMgUENJIGNvbnRyb2xsZXIgPT09CjAw OjE0LjAgU01CdXMgWzBjMDVdOiBBZHZhbmNlZCBNaWNybyBEZXZpY2VzLCBJbmMuIFtBTURdIEZD SCBTTUJ1cyBDb250cm9sbGVyIFsxMDIyOjc5MGJdIChyZXYgNzEpCglTdWJzeXN0ZW06IEdpZ2Fi eXRlIFRlY2hub2xvZ3kgQ28uLCBMdGQgRGV2aWNlIFsxNDU4OjUwMDFdCglLZXJuZWwgbW9kdWxl czogaTJjX3BpaXg0LCBzcDUxMDBfdGNvCjAwOjE0LjAgU01CdXM6IEFkdmFuY2VkIE1pY3JvIERl dmljZXMsIEluYy4gW0FNRF0gRkNIIFNNQnVzIENvbnRyb2xsZXIgKHJldiA3MSkKCVN1YnN5c3Rl bTogR2lnYWJ5dGUgVGVjaG5vbG9neSBDby4sIEx0ZCBEZXZpY2UgNTAwMQoJQ29udHJvbDogSS9P KyBNZW0rIEJ1c01hc3Rlci0gU3BlY0N5Y2xlLSBNZW1XSU5WLSBWR0FTbm9vcC0gUGFyRXJyLSBT dGVwcGluZy0gU0VSUi0gRmFzdEIyQi0gRGlzSU5UeCsKCVN0YXR1czogQ2FwLSA2Nk1IeisgVURG LSBGYXN0QjJCLSBQYXJFcnItIERFVlNFTD1tZWRpdW0gPlRBYm9ydC0gPFRBYm9ydC0gPE1BYm9y dC0gPlNFUlItIDxQRVJSLSBJTlR4LQoJSU9NTVUgZ3JvdXA6IDEwCglLZXJuZWwgbW9kdWxlczog aTJjX3BpaXg0LCBzcDUxMDBfdGNvCgoKPT09IEkvTyByZXNvdXJjZSByZXNlcnZhdGlvbiA9PT0K ICAwMDAwLTAwMDAgOiBQTlAwQjAwOjAwCgo9PT0gUmVsZXZhbnQga2VybmVsIG1lc3NhZ2VzID09 PQpPY3QgMzAgMTA6NTE6NTkgWWF6b3VkaVBjIGtlcm5lbDogQklPUy1lODIwOiBbbWVtIDB4MDAw MDAwMDAwYjAwMDAwMC0weDAwMDAwMDAwMGIwMjBmZmZdICBkZXZpY2UgcmVzZXJ2ZWQKT2N0IDMw IDEwOjUxOjU5IFlhem91ZGlQYyBrZXJuZWw6IFBNOiBoaWJlcm5hdGlvbjogUmVnaXN0ZXJlZCBu b3NhdmUgbWVtb3J5OiBbbWVtIDB4MGIwMDAwMDAtMHgwYjAyMGZmZl0KT2N0IDMwIDEwOjUxOjU5 IFlhem91ZGlQYyBrZXJuZWw6IGU4MjA6IHJlZ2lzdGVyIFJBTSBidWZmZXIgcmVzb3VyY2UgW21l bSAweDBiMDAwMDAwLTB4MGJmZmZmZmZdCk9jdCAzMCAxMDo1MTo1OSBZYXpvdWRpUGMga2VybmVs OiBhY3BpIFBOUDBDMDI6MDM6IFJlc2VydmVkIFtpbyAgMHgwYjAwLTB4MGIwZl0KT2N0IDMwIDEw OjUxOjU5IFlhem91ZGlQYyBrZXJuZWw6IHJ0Y19jbW9zIFBOUDBCMDA6MDA6IFJUQyBjYW4gd2Fr ZSBmcm9tIFM0Ck9jdCAzMCAxMDo1MTo1OSBZYXpvdWRpUGMga2VybmVsOiBydGNfY21vcyBQTlAw QjAwOjAwOiByZWdpc3RlcmVkIGFzIHJ0YzAKT2N0IDMwIDEwOjUxOjU5IFlhem91ZGlQYyBrZXJu ZWw6IHJ0Y19jbW9zIFBOUDBCMDA6MDA6IHNldHRpbmcgc3lzdGVtIGNsb2NrIHRvIDIwMjYtMTAt MzBUMDY6NTE6NTEgVVRDICgxNzkzMzQzMTExKQpPY3QgMzAgMTA6NTE6NTkgWWF6b3VkaVBjIGtl cm5lbDogcnRjX2Ntb3MgUE5QMEIwMDowMDogYWxhcm1zIHVwIHRvIG9uZSBtb250aCwgeTNrLCAx MTQgYnl0ZXMgbnZyYW0KT2N0IDMwIDEwOjUxOjU5IFlhem91ZGlQYyBrZXJuZWw6IEFDUEkgV2Fy bmluZzogU3lzdGVtSU8gcmFuZ2UgMHgwMDAwMDAwMDAwMDAwQjAwLTB4MDAwMDAwMDAwMDAwMEIw OCBjb25mbGljdHMgd2l0aCBPcFJlZ2lvbiAweDAwMDAwMDAwMDAwMDBCMDAtMHgwMDAwMDAwMDAw MDAwQjBGIChcR1NBMS5TTUJJKSAoMjAyNjA0MDgvdXRhZGRyZXNzLTIwNCkKT2N0IDMwIDEwOjUx OjU5IFlhem91ZGlQYyBrZXJuZWw6IEFDUEk6IE9TTDogUmVzb3VyY2UgY29uZmxpY3Q7IEFDUEkg c3VwcG9ydCBtaXNzaW5nIGZyb20gZHJpdmVyPwpPY3QgMzAgMTE6MjQ6MjUgWWF6b3VkaVBjIGtl cm5lbDogQUNQSSBXYXJuaW5nOiBTeXN0ZW1JTyByYW5nZSAweDAwMDAwMDAwMDAwMDBCMDAtMHgw MDAwMDAwMDAwMDAwQjA4IGNvbmZsaWN0cyB3aXRoIE9wUmVnaW9uIDB4MDAwMDAwMDAwMDAwMEIw MC0weDAwMDAwMDAwMDAwMDBCMEYgKFxHU0ExLlNNQkkpICgyMDI2MDQwOC91dGFkZHJlc3MtMjA0 KQpPY3QgMzAgMTE6MjQ6MjUgWWF6b3VkaVBjIGtlcm5lbDogQUNQSTogT1NMOiBSZXNvdXJjZSBj b25mbGljdDsgQUNQSSBzdXBwb3J0IG1pc3NpbmcgZnJvbSBkcml2ZXI/Cg== --b1=_tas4pBrJGPaOHPqnjwdzTAuh5bgQkqaAUyBar8YW1vc--