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 30C2AC6FA8B for ; Wed, 21 Sep 2022 07:15:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229975AbiIUHPg (ORCPT ); Wed, 21 Sep 2022 03:15:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58274 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230000AbiIUHP3 (ORCPT ); Wed, 21 Sep 2022 03:15:29 -0400 Received: from wp530.webpack.hosteurope.de (wp530.webpack.hosteurope.de [IPv6:2a01:488:42:1000:50ed:8234::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8FEAB5508F; Wed, 21 Sep 2022 00:15:19 -0700 (PDT) Received: from [2a02:8108:963f:de38:eca4:7d19:f9a2:22c5]; authenticated by wp530.webpack.hosteurope.de running ExIM with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) id 1oatwz-0000gU-He; Wed, 21 Sep 2022 09:15:17 +0200 Message-ID: Date: Wed, 21 Sep 2022 09:15:17 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.2.1 Subject: How to quickly resolve the IOMMU regression that currently plagues a lot of people in 5.19.y Content-Language: en-US, de-DE From: Thorsten Leemhuis To: Greg KH Cc: Joerg Roedel , Lu Baolu , iommu@lists.linux.dev, "stable@vger.kernel.org" , "regressions@lists.linux.dev" , LKML , Linus Torvalds , Sasha Levin References: <1d1844f0-c773-6222-36c6-862e14f6020d@leemhuis.info> In-Reply-To: <1d1844f0-c773-6222-36c6-862e14f6020d@leemhuis.info> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-bounce-key: webpack.hosteurope.de;regressions@leemhuis.info;1663744521;8cf85169; X-HE-SMSGID: 1oatwz-0000gU-He Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [resend with proper subject, sorry for the noise] [note to self: don't get distracted when writing the subject] On 21.09.22 08:53, Thorsten Leemhuis wrote: > Hi Greg! As you likely heard already, 5.19.9 introduced a regression > that breaks Thunderbolt and USB-C docks (and apparently Wifi in some > cases as well) on quite a few (many?) modern systems. It's one of those > problems where I think "hey, we ideally should fix this in stable as > fast as possible" we briefly talked about last week on the LPC hallways. > That made me wonder how to actually archive that in this particular case > while keeping all involved parties happy and not skipping any CI testing > queues considered important. > > FWIW, here are a few few reports about the issue (I assume there are > some for Arch Linux and openSUSE Tumbleweed as well, but didn't check). > > https://lore.kernel.org/linux-iommu/485A6EA5-6D58-42EA-B298-8571E97422DE@getmailspring.com/ > https://bugzilla.kernel.org/show_bug.cgi?id=216497 > https://bugzilla.redhat.com/show_bug.cgi?id=2128458 > https://bugzilla.redhat.com/show_bug.cgi?id=2127753 > > A revert of the culprit (9cd4f1434479f ("iommu/vt-d: Fix possible > recursive locking in intel_iommu_init()"); in 5.19.y it's 9516acba29e3) > for mainline is here: > https://lore.kernel.org/lkml/20220920081701.3453504-1-baolu.lu@linux.intel.com/ > > A few hours ago the revert was queued to get send to Joerg: > https://lore.kernel.org/linux-iommu/20220921024054.3570256-1-baolu.lu@linux.intel.com/ > > I fear it could easily take another week to get this fixed in stable > depending on how fast the patch makes it to mainline and the timing of > the next 5.19.y release and its -rc phase. That to me sounds like way > too long for a problem like this that apparently plagues quite a few > people. > > That made me wonder: would you in cases like this be willing to start > the -rc phase for a interim 5.19.y release with just that revert while > it's still heading towards mainline? Then the CI systems that test > stable -rcs could chew on things already; and the new stable release > could go out right after the revert landed in mainline (unless the > testing finds any problems, of course). > > Ciao, Thorsten > >