From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793039572; b=LjPFlRsU/Kl8oPaEUsLL/znVS5IabN1mpehs1jZRLbhgGlnQ0XHZVu0UH6y2/YmsaXN0 J4uKlkTfiF8Sficekxog/aqcmXzIFPE+wHzFPsSfUV8ZdpBfPMPPkKBAgdIq4GwDy3nJJ l2PJDlYCWmu8KQHv4PTbw3IyelUnlw6pmzU3zhhR1qKdp9lCd0U+laBL65+QkCq15NLFd /qROvLMxd5T33lGvms0acoMA8ZVEc6wMtLm9WBR4R8IOQ4jPHF5r39/cR9KXtV6BMOT25 nY1C4UUMXpbR3h3zkjwZql74XXgmszdhgKd30wwNJkLPgZ0Qq6ipoOEUC1aZ4pHX8KA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793039572; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: MIME-Version:Content-Type:Content-Disposition: Content-Transfer-Encoding:In-Reply-To; bh=Y656h6emly7vQtOx07lZuRhTn1i7lVTDjqa7PpKqvx8=; b=pHqO351CqjAemkOwyFMq0ojWqF5HcEQ74siN62EgG0iPIW5HCpiufShZocQLl3sM3fB0 7l1p1jlks86PHCwqMMAZzsSIRpOjLSkiAjhyZpQg8zB5GxzHh5eAo7D/CDh7gneE3iJCD SaOFrg3Vdy+SMqXfZLpTXlOlIiX69T+Q4tSPqe1WgrRsBQ3WGW4W9McWNy3ljPs03HrR2 78wRar906FTn49b46omKVtM4hbIDnEDeJjKzdSwsrn6+7L0o08/9xThY9/Nm0iXzK7AYM KilCsx9MxKhVzekwmYdTQ65OBct8RKo30gfIcjbqwHKEr07z91PzQvOYcalwhTIfGBg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=k0Ekg354; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (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 EA787606A326; Mon, 26 Oct 2026 18:32:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=k0Ekg354 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 410C71F01825; Mon, 26 Oct 2026 18:32:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793039571; bh=Y656h6emly7vQtOx07lZuRhTn1i7lVTDjqa7PpKqvx8=; h=Date:From:To:Cc:Subject:In-Reply-To; b=k0Ekg354iaJT6YupxoOlPphuD8uLZIHh6yvGX6y5eiJKkP3CpDlxXHxrmx+WMVNGo AqQzXiYfZjysQfb9/soz9Lg5eCnaDKeMAyxGcYkIznG5+jn6Y/HsYpKczSFfos0AEW AcCuT/O2qp26rucfEjQjkO25murjqyJDtWsvs8RmDZYDBC1JQ3bRa2h4eW/RAgKots VIA/U0mo61RYJNx+ie0Jjoj8w0THxCAuPESWlCAmZCKuV5nFepDpGoz0WH0vMKYODl 8rnN0AUOIm/XML9X2IXfwRYZLJxvMI3n5sjIgjnkW25uwQ0fkYw9woURAPGTBql9/X DplKslTuXs0rQ== Date: Mon, 26 Oct 2026 13:32:50 -0500 From: Bjorn Helgaas To: Nicolas Chauvet Cc: Karl Mehltretter , Bjorn Helgaas , Thierry Reding , Jonathan Hunter , linux-pci@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] PCI: quirks: Skip nv_msi_ht_cap_quirk when host bridge 00:00.0 is absent Message-ID: <20261026183250.GA332821@bhelgaas> 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: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Sat, Oct 24, 2026 at 07:52:02PM +0200, Nicolas Chauvet wrote: > Le sam. 24 oct. 2026 à 19:25, Karl Mehltretter > a écrit : > > > > __nv_msi_ht_cap_quirk() runs on all PCI_VENDOR_ID_NVIDIA devices to > > enable or disable HyperTransport MSI mapping relative to a host bridge > > at bus 0, slot 0, function 0. > > > > On NVIDIA Tegra SoCs (such as Tegra210 on Jetson Nano), the PCIe > > controller exposes root ports at 00:01.0 and 00:02.0 with no device at > > 00:00.0, and the root port's HT MSI mapping capability is already > > disabled (found == 1). Looking up 00:00.0 returns NULL and logs a > > false-positive warning on every boot: > > > > pci 0000:00:02.0: nv_msi_ht_cap_quirk didn't locate host bridge > > > > Return silently when no 00:00.0 device exists on the domain, matching > > nv_ht_enable_msi_mapping(). > > > > Assisted-by: LLM > > Signed-off-by: Karl Mehltretter > > --- > > Observed on a Jetson Nano 4GB (Tegra210, p3450-0000) booting v7.3 > > (c03c1a14507d), where the Tegra PCIe controller (1003000.pcie) > > enumerates the active root port at 0000:00:02.0 ([10de:0faf]) with no > > 0000:00:00.0 device on bus 00: > > > > pci 0000:00:02.0: [10de:0faf] type 01 class 0x060400 PCIe Root Port > > pci 0000:00:02.0: nv_msi_ht_cap_quirk didn't locate host bridge > > There is this patch that was well tested on the tegra side (but likely > less on the older x86 nv cases) > https://codeberg.org/libre-tegra/linux/commit/63f7810994f4d2866a27b753ec8d5bc36e84373c If anybody thinks this is better, please post with the appropriate commit log and signed-off-by.