From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 024263DBD76 for ; Sun, 18 Oct 2026 20:20:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792354804; cv=none; b=OvWwbPEJxSNk0bJm5pqndsSk0g+UNgBNWPvPPSPqIRmGmjv6L+mJm98LKU/MjFLfJd183WOfM3uVCiNxUEzmFU7qlo34aPfuvPaixKZXSQygduxyPATEDkCpDw6jl1jQSgr0B8hMosrowCHqFXGiUR/fbKIQ2DSBRI4IRmN0QJc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792354804; c=relaxed/simple; bh=gbMLJcTVulnft8kVuQrgyddCRO8ijTxbcMTNOX0tt2o=; h=Message-ID:From:Subject:To:In-Reply-To:References:Content-Type: Date; b=ml7Mur+Om2cK+ZsHFFGgxYnZ56etLTXZFnNHC+m5Qw5uV1G8HB/dJh/y/qDCJ05M7sTFkz3DCEP6YnuSESYPgr3pEtOPz37hn8L63IsTMj3p8+5aPWY3ubwK+GgsBe36xIZngcFEU52AGGLHQGipa1P9oCIogeBMZPkGlztmmfw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Fu+0nfHF; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Fu+0nfHF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 94D5C1F000C4; Sun, 18 Oct 2026 20:20:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792354803; bh=gbMLJcTVulnft8kVuQrgyddCRO8ijTxbcMTNOX0tt2o=; h=From:Subject:Reply-To:To:In-Reply-To:References:Date; b=Fu+0nfHFF3HJF32gfmu8+vN3IVKuUMLl6gtsoFyDxAxi9Qlmy0biMPDiGHHnaWVr3 iduT3ubeqN+kK97QlLmMapu5CrWwithtsnJSHpHYz/DPKeIa9gdaZLIzn4Kg4c0haj UfZFVtptIwhtJiIMb+aJF/VMWIoR9t9cRTqp8pqtLGUBSs6k80/J2KrDxI8b2qCW8Y I3kYNkDmGA9aV5d+J8TL1k4sgG68YYrxPepojypgA6RjAsXLChRrNSbV/hlqqjiTJM 1koois8twsN4W+oJRf5mQhqMxaosxoEfs1LpgUkWbFEAuSOELQVq+mHm0/Q3HTaibG wgTXQrT6hO8KA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH] PCI: Avoid bus reset on NVIDIA GB202 and GB203 GPUs Reply-To: sashiko-reviews@lists.linux.dev To: mark-ship-it , linux-pci@vger.kernel.org In-Reply-To: <20261018201727.96924-1-williamwoodstock79@gmail.com> References: <20261018201727.96924-1-williamwoodstock79@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sun, 18 Oct 2026 20:20:03 +0000 Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > NVIDIA GB202 (GeForce RTX 5090, RTX PRO 6000) and GB203 (GeForce RTX > 5080/5070 Ti/5070) GPUs train their link at x16 at boot, but after a > Secondary Bus Reset the link comes back at x8 and stays there until the > next cold boot. >=20 > The GPU's HD Audio function (e.g. 10de:22e9 on GB203) has no reset method, > so when both functions are assigned to a VM, vfio-pci falls back to a bus > reset at VM start and again at release, and the GPU then runs at half > width. Assigning only function 0 avoids the bus reset because the GPU > itself supports FLR, which is why the problem is usually reported as > "passing the audio function breaks x16". >=20 > Observed on an RTX 5080 (10de:2c02) behind an AMD Root Port, kernel > 7.0.14, Proxmox VE host with a Windows 11 Pro guest: >=20 > [ ... ] > kept x16. >=20 > Link: https://forum.proxmox.com/threads/asus-x870e-pcie-x8-bifurcation-bu= g-with-rtx-5090-vfio-passthrough.178461/ >=20 > Signed-off-by: mark-ship-it Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261018201727.9692= 4-1-williamwoodstock79@gmail.com?part=3D1