From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 231DCC32774 for ; Tue, 23 Aug 2022 06:06:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240463AbiHWGGO (ORCPT ); Tue, 23 Aug 2022 02:06:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40910 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238558AbiHWGGK (ORCPT ); Tue, 23 Aug 2022 02:06:10 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B2B4848C91 for ; Mon, 22 Aug 2022 23:06:07 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 48C1020D55; Tue, 23 Aug 2022 06:06:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1661234766; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=XXmRV3j3jF/dboZ9mDq8vtAInRpeHISrunDZMf2kdqg=; b=oxmE7hJLQTm7BQvECemTCYzdzLzaDd0IGLlQl5RK1jFQuKSr1Om/C8URBWdybARUR9Jdz4 WxO43zzDdEbHXizcqUtJ0pyHaoqmeCx3zpA097FR2Ztgm8KX1/5VdGdrdQizlw3XGjsygZ OgVCYA2/YemrSYSGeOl4eB82Hr3x2O4= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1661234766; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=XXmRV3j3jF/dboZ9mDq8vtAInRpeHISrunDZMf2kdqg=; b=zU94cY81qyXBVJs6MaQGlgHjH3rKP3Zt/ovNj9S/YU8gV1QQ5jBQNBk6NbLHrGp4Rll41P 9XZq5x9X08Nl5GCA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 0ED6813A89; Tue, 23 Aug 2022 06:06:06 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 9ZW7Ak5uBGN4IAAAMHmgww (envelope-from ); Tue, 23 Aug 2022 06:06:06 +0000 Date: Tue, 23 Aug 2022 08:06:05 +0200 Message-ID: <87h723sdde.wl-tiwai@suse.de> From: Takashi Iwai To: Jason Gunthorpe Cc: Takashi Iwai , Lu Baolu , Joerg Roedel , Greg Kroah-Hartman , Bjorn Helgaas , Robin Murphy , Eric Auger , regressions@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [REGRESSION 5.19.x] AMD HD-audio devices missing on 5.19 In-Reply-To: <20220823010021.GA5967@nvidia.com> References: <874jy4cqok.wl-tiwai@suse.de> <20220823010021.GA5967@nvidia.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) Emacs/27.2 Mule/6.0 MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 23 Aug 2022 03:00:21 +0200, Jason Gunthorpe wrote: > > On Mon, Aug 22, 2022 at 04:12:59PM +0200, Takashi Iwai wrote: > > Hi, > > > > we've received regression reports about the missing HD-audio devices > > on AMD platforms, and this turned out to be caused by the commit > > 512881eacfa72c2136b27b9934b7b27504a9efc2 > > bus: platform,amba,fsl-mc,PCI: Add device DMA ownership management > > > > The details are found in openSUSE bugzilla: > > https://bugzilla.suse.com/show_bug.cgi?id=1202492 > > > > The problem seems to be that HD-audio (both onboard analog and HDMI) > > PCI devices are assigned to the same IOMMU group as AMD graphics PCI > > device, and once after the AMDGPU is initialized beforehand, those > > audio devices can't be probed since iommu_device_use_default_domain() > > returns -EBUSY. > > Can you describe exactly what drivers are involved in this? If it is > the above commit then several devices are sharing an iommu group and > one of them (well, the only one already attached, I suppose) has made > the group unsharable. > > With grep I don't see an obvious place where the AMDGPU driver would > mess with the iommu configuration, so I have no guess. I have also no concrete clue, either :) At least, drivers/gpu/drm/amd/amdkfd/kfd_iommu.c calls amd_iommu_init_device(), and this invokes iommu_attach_group(), which may change group->domain. But it was just my wild guess, and it might be others, indeed. > It would be good to have some debugging to confirm if it is > group->owner (should be impossible, suggests memory corruption if it > is) or group->domain != group->default_domain. > > Most likely it is the later, but I can't see how that could happen on > a system like this.. There is no obvious manipulation in AMDGPU, for > instance. > > So debugging to find the backtrace for exactly when > group->domain != group->default_domain > Occurs for the troubled group would be necessary. OK, will try to build a test kernel with some debug prints and ask the reporters. It may take some time. > If you know the group name it would be easy enough to cook a patch to > throw a warn on when group->domain changes > > > domain assignment. In anyway, disabling IOMMU works around the > > problem, and passing driver_managed_dma flag to the HD-audio driver > > was also confirmed to work around it, too. > > Disabling iommu removes the groups entirely, this disables the check. > > driver_managed_dma disables the check entirely - which raises the > question how the driver is even able to work.. > > If the domain is not the default_domain it is very surprising that DMA > can work at all. Since it does, something really odd has happened. Yeah it's something odd ;) I'm not sure whether the people tested HD-audio capability at all, but otherwise they might have noticed. Takashi