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 7A374568550 for ; Wed, 9 Sep 2026 16:57:02 +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=1788973023; cv=none; b=gMgFeArKbJnDOrP4477/bmS0hkzJ0GHJBfQ5oE/nC4st+gGswsvAkAWiHE0aVa2dmgh4gi6QFKfQ+JF8k1eP4sXiGxYstg8r7YRw7uJwDcpTx8OYVxvV3UmrxYU/xvgRqVs1NnEzomUU7H5ZA/XLLq+Z0E4DiyUwrTPpYmR1VuE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788973023; c=relaxed/simple; bh=o3O4Th+Wog8c0y6YXUpDS8G6RLAnIuXUbsxl79lo2Lk=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=eipVAM7AYKETbhNaMb+GOn0YkWLpHTkcJ7fBqGFRtLAJSp1528FzxglYNFe27cKdxyRHNZv85I3Kg7NNxaURRs0G0lH/Zn1vLe+r5KhltVRLYILDT+bEVR/SicWPW/gb84HjkiVcW/+KgVml94qEEfPETUHuaS0b9cZTFaOBpos= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BCjm57dk; 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="BCjm57dk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B5D191F000FF; Wed, 9 Sep 2026 16:57:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788973021; bh=o3O4Th+Wog8c0y6YXUpDS8G6RLAnIuXUbsxl79lo2Lk=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=BCjm57dkhKa6l3I9C+IkZU0OmQltYbUS1YWm1vrH+afSg13Txc/mRO0gAgupN760n EnHMxm1/j69QJSeoDVp7sJHQ60rj3p+dB+i033zSwgoWeN1dk+yHSldB/T1imLhpk6 pO06cua5xtsWta9RGpKtId8ymgU1iUJRfKxJf/5Pj+v4K4owfl1L47B2OdhK36nerS VVvjpMFAruPfbdXHowbrdfRZFwHQI6M3oyLl/wgCJZQZShMCIXj/XzX1626B1Z6yu6 U2exw3ANTiCCuqNC6R2p80jE58ynODP2MgpGd/2jOIeZjEfTEAShZhdzTS5/yT5U8Q TEkxWYZ1cYKcw== From: sashiko-bot@kernel.org Subject: Re: [PATCH V4] PCI/MSI: Skip MSI/MSI-X programming while the channel is offline Reply-To: sashiko-reviews@lists.linux.dev To: "Vidya Sagar" Cc: linux-pci@vger.kernel.org In-Reply-To: <20260909164908.2562818-1-vidyas@nvidia.com> References: <20260825172719.4153402-1-vidyas@nvidia.com> <20260909164908.2562818-1-vidyas@nvidia.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 09 Sep 2026 16:57:01 +0000 Message-Id: <20260909165701.B5D191F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > The MSI-X Table lives in device MMIO space behind a BAR and the MSI Mask > register in Configuration Space, so neither is reachable while the Link > is down. While a Downstream Port has the Link contained by DPC it > completes these accesses with Unsupported Request, and reads return all > ones. >=20 > If the upstream Root Port implements the RP Extensions for DPC, it > additionally reports that UR completion as an RP PIO error and triggers a > second containment event, this time at the Root Port, which contains > every device below it. So a contained Link on one Downstream Port turns > into a far wider outage that takes down unrelated devices. >=20 > pci_free_irq_vectors() is called from driver error_detected() and > prepare-for-reset callbacks, i.e. while the Link is contained and before > the reset and the pci_restore_state() that follows it, and it masks every > [ ... ] >=20 > This does not attempt to make every Configuration Space access safe > while the Link is contained. >=20 > Signed-off-by: Vidya Sagar Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260909164908.2562= 818-1-vidyas@nvidia.com?part=3D1