From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bmailout1.hostsharing.net (bmailout1.hostsharing.net [83.223.95.100]) (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 9A13F26D4E7 for ; Wed, 2 Jul 2025 13:29:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=83.223.95.100 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751462999; cv=none; b=jvVC8KAi0bNqYdA4cR74cgfQwqiyUf0QjGvSHNU6oU6+c2rDWCb5N6ZMDvgAhKUCLwDRZzTVtk4u2oBZpa7ETPufgDtHmyDmhZMV4vUCAmi+jIsYyhrNe9LGlEaNyDPAayWfAsW+nk2lvP3UcqZREpqb8X3lO5NjI8XB0X0UI9Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751462999; c=relaxed/simple; bh=CWd2WKm0oM/5FeHrFr3gmO0oEPsXtMk0+Zip/vYuZ7o=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=LIrG8ufFN9bYRiyoEI1btDDtffito9k9FyNAITYhWuBdH+pn0qpfhdqQd4vfZitNjLgoI5w7jSJdYE0eGLlRlHEatAzyUKv3DaEgvYGrX4hdoLymfK2W0Nlvg0kfTvWNRySg9xXWkkvj83LuPuYdm4DHbbICq4vNJwwgh8ndbRc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de; spf=none smtp.mailfrom=h08.hostsharing.net; arc=none smtp.client-ip=83.223.95.100 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=h08.hostsharing.net Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS RSA CA G1" (verified OK)) by bmailout1.hostsharing.net (Postfix) with ESMTPS id 1C0102C06E2D; Wed, 2 Jul 2025 15:29:49 +0200 (CEST) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 05510402D89; Wed, 2 Jul 2025 15:29:49 +0200 (CEST) Date: Wed, 2 Jul 2025 15:29:48 +0200 From: Lukas Wunner To: Hans de Goede Cc: Ben Hutchings , David Airlie , Bjorn Helgaas , Joerg Roedel , Suravee Suthikulpanit , Andi Kleen , Ahmed Salem , Borislav Petkov , dri-devel@lists.freedesktop.org, iommu@lists.linux.dev, linux-pci@vger.kernel.org, Thomas Gleixner Subject: Re: [PATCH] agp/amd64: Bind to unsupported devices only if AGP is present Message-ID: References: <279f63810875f2168c591aab0f30f8284d12fe02.camel@decadent.org.uk> <9077aab5304e1839786df9adb33c334d10c69397.camel@decadent.org.uk> <98012c55-1e0d-4c1b-b650-5bb189d78009@redhat.com> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: [cc += tglx, start of thread: https://lore.kernel.org/r/f8ff40f35a9a5836d1371f60e85c09c5735e3c5e.1750497201.git.lukas@wunner.de/ ] On Wed, Jul 02, 2025 at 12:47:49PM +0200, Lukas Wunner wrote: > On Mon, Jun 30, 2025 at 01:10:24PM +0200, Hans de Goede wrote: > > ping? It would be good to get some consensus on how to > > fix this and move forward with a fix. Either the patch from > > this thread; or my patch: > > > > https://lore.kernel.org/dri-devel/20250625112411.4123-1-hansg@kernel.org/ > > > > Works for me, the most important thing here is to get this > > regression fixed. > > You seem to have a machine where you can trigger the > "Resources present before probing" message. > > Would you mind enabling CONFIG_DEBUG_DEVRES=y and adding > "log_devres=1" to the kernel command line so that we > can understand what kind of resource is attached to > the AMD IOMMU, and where that happens. > > I don't see invocations of devm_*() in arch/x86/ or > drivers/iommu/amd/ that would explain the error message. I just remembered that an MSI is set up for the AMD IOMMU. And sure enough: amd_iommu_enable_interrupts() iommu_init_irq() iommu_setup_msi() pci_enable_msi() __pci_enable_msi_range() pci_setup_msi_device_domain() pci_create_device_domain() msi_create_device_irq_domain() msi_setup_device_data() msi_sysfs_create_group() devm_device_add_group() ... introduced by bf5e758f02fc ("genirq/msi: Simplify sysfs handling"). Not sure if this is the only one or if there are other resources added anywhere else for the driver-less AMD IOMMU. We'd have to rework MSI handling to not use devm_*(), so that MSIs can be requested for a device without it being bound to a driver. But I suspect tglx may have deliberately designed it to not support that, in which case what the AMD IOMMU driver does is somewhat dodgy... Thanks, Lukas