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 62076C433EF for ; Mon, 23 May 2022 20:04:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232081AbiEWUEn (ORCPT ); Mon, 23 May 2022 16:04:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232060AbiEWUEl (ORCPT ); Mon, 23 May 2022 16:04:41 -0400 Received: from mail-yb1-xb2d.google.com (mail-yb1-xb2d.google.com [IPv6:2607:f8b0:4864:20::b2d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1ECC9F13 for ; Mon, 23 May 2022 13:04:40 -0700 (PDT) Received: by mail-yb1-xb2d.google.com with SMTP id d137so27311992ybc.13 for ; Mon, 23 May 2022 13:04:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=u1AipD1OfrmQcB3YUOaC7P4EIOVqCxquxh0+AE+xuhM=; b=bQzOkbeNz00bM35Ce99+u6O7FvwcbMq3CbiwHzibWAm6u6rINPbk7M+Gwf+K9Rpfqf Bf403twpWA0WD0G/TeiGjK7xOqCHIbbjcEyaY7BokFUQ+zKuBOPZ4uuNji6TV8e8F0C1 OiSHL6d1UFbmnZn05rjy7t5aWkkhI9KCK9PlriUExXYqGdsnCTQfyAuJZt5YfiCD5x4p PKKVhF6lcNgu2psiwb4uusrHWD7/H5PDQpYT3YIO6SB5vgxXpWhixe5z1M+Sg7r5WGTG kStV8jBQu/gFdCpVP2vrKt9lgnlvuXrGHW8QBgL9FPZgCDY30zwKLwvPAhDhx3FPGx8x PsTQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=u1AipD1OfrmQcB3YUOaC7P4EIOVqCxquxh0+AE+xuhM=; b=LktEnwIEeIfM1MhuE0PPNtvRM9/3p375A9krsJ0Jczk4MN2Jv0kEKiFW+8Z9vsQoxa 3XerfEBISV3HQrQR6ubARqD37D2YfNxQ7qTVVn72MgctAeH7g98AZmwBp1SaxYalgYWJ 5Qzx34lhYtFtiaMk1KJM5uAYNp0Th5kndaNcxw0oENR+zCMwb/hL14BEKoTEdWzZ2W1N Md+Ct2xOz4PZae1W1vBUWovEdXr0c8Sp8+YdK3FIZnH1N49OIRvg0pswOeaLwEacBGw8 PWIw6/e0+TyjOkzZjYfv2Gd+AeXxx95ZQ7KUg/7tafFS9I3M0r3o3UZR48KbBqAN9oAL M/sA== X-Gm-Message-State: AOAM53063oLX03hW1H2u3jRPhj00X9OoDwDSYp88LHmlh5H78jVjc/Ev t01sGPe0We9HgO67meoh8R5tZTB8PxONRZt60beK6g== X-Google-Smtp-Source: ABdhPJzqi3uJx736pHwpoReDWxmaiJiRfwvNOrYnqDbU07+DT5iV9p+v8KIvHm54c3ZBoXT3vDZcWATWAm//Q1iK/LY= X-Received: by 2002:a05:6902:70e:b0:64f:2e28:d64a with SMTP id k14-20020a056902070e00b0064f2e28d64amr23757981ybt.80.1653336279141; Mon, 23 May 2022 13:04:39 -0700 (PDT) MIME-Version: 1.0 References: <20220429220933.1350374-1-saravanak@google.com> In-Reply-To: From: Saravana Kannan Date: Mon, 23 May 2022 13:04:03 -0700 Message-ID: Subject: Re: [PATCH v1] driver core: Extend deferred probe timeout on driver registration To: Nathan Chancellor Cc: Jonathan Corbet , Greg Kroah-Hartman , "Rafael J. Wysocki" , "Rafael J. Wysocki" , Rob Herring , Linus Walleij , Will Deacon , Ulf Hansson , Kevin Hilman , Thierry Reding , Mark Brown , Pavel Machek , Geert Uytterhoeven , Yoshihiro Shimoda , Paul Kocialkowski , linux-gpio@vger.kernel.org, linux-pm@vger.kernel.org, iommu@lists.linux-foundation.org, kernel-team@android.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org On Mon, May 23, 2022 at 8:17 AM Nathan Chancellor wrote: > > On Fri, May 20, 2022 at 05:15:55PM -0700, Saravana Kannan wrote: > > On Fri, May 20, 2022 at 5:04 PM Nathan Chancellor wrote: > > > > > > On Fri, May 20, 2022 at 04:49:48PM -0700, Saravana Kannan wrote: > > > > On Fri, May 20, 2022 at 4:30 PM Nathan Chancellor wrote: > > > > > > > > > > Hi Saravana, > > > > > > > > > > On Fri, Apr 29, 2022 at 03:09:32PM -0700, Saravana Kannan wrote: > > > > > > The deferred probe timer that's used for this currently starts at > > > > > > late_initcall and runs for driver_deferred_probe_timeout seconds. The > > > > > > assumption being that all available drivers would be loaded and > > > > > > registered before the timer expires. This means, the > > > > > > driver_deferred_probe_timeout has to be pretty large for it to cover the > > > > > > worst case. But if we set the default value for it to cover the worst > > > > > > case, it would significantly slow down the average case. For this > > > > > > reason, the default value is set to 0. > > > > > > > > > > > > Also, with CONFIG_MODULES=y and the current default values of > > > > > > driver_deferred_probe_timeout=0 and fw_devlink=on, devices with missing > > > > > > drivers will cause their consumer devices to always defer their probes. > > > > > > This is because device links created by fw_devlink defer the probe even > > > > > > before the consumer driver's probe() is called. > > > > > > > > > > > > Instead of a fixed timeout, if we extend an unexpired deferred probe > > > > > > timer on every successful driver registration, with the expectation more > > > > > > modules would be loaded in the near future, then the default value of > > > > > > driver_deferred_probe_timeout only needs to be as long as the worst case > > > > > > time difference between two consecutive module loads. > > > > > > > > > > > > So let's implement that and set the default value to 10 seconds when > > > > > > CONFIG_MODULES=y. > > > > > > > > > > > > Cc: Greg Kroah-Hartman > > > > > > Cc: "Rafael J. Wysocki" > > > > > > Cc: Rob Herring > > > > > > Cc: Linus Walleij > > > > > > Cc: Will Deacon > > > > > > Cc: Ulf Hansson > > > > > > Cc: Kevin Hilman > > > > > > Cc: Thierry Reding > > > > > > Cc: Mark Brown > > > > > > Cc: Pavel Machek > > > > > > Cc: Geert Uytterhoeven > > > > > > Cc: Yoshihiro Shimoda > > > > > > Cc: Paul Kocialkowski > > > > > > Cc: linux-gpio@vger.kernel.org > > > > > > Cc: linux-pm@vger.kernel.org > > > > > > Cc: iommu@lists.linux-foundation.org > > > > > > Signed-off-by: Saravana Kannan > > > > > > > > > > I bisected a boot hang with ARCH=s390 defconfig in QEMU down to this > > > > > change as commit 2b28a1a84a0e ("driver core: Extend deferred probe > > > > > timeout on driver registration") in next-20220520 (bisect log below). > > > > > > > > > > $ make -skj"$(nproc)" ARCH=s390 CROSS_COMPILE=s390x-linux-gnu- defconfig bzImage > > > > > > > > > > $ timeout --foreground 15m stdbuf -oL -eL \ > > > > > qemu-system-s390x \ > > > > > -initrd ... \ > > > > > -M s390-ccw-virtio \ > > > > > -display none \ > > > > > -kernel arch/s390/boot/bzImage \ > > > > > -m 512m \ > > > > > -nodefaults \ > > > > > -serial mon:stdio > > > > > ... > > > > > [ 2.077303] In-situ OAM (IOAM) with IPv6 > > > > > [ 2.077639] NET: Registered PF_PACKET protocol family > > > > > [ 2.078063] bridge: filtering via arp/ip/ip6tables is no longer available by default. Update your scripts to load br_netfilter if you need this. > > > > > [ 2.078795] Key type dns_resolver registered > > > > > [ 2.079317] cio: Channel measurement facility initialized using format extended (mode autodetected) > > > > > [ 2.081494] Discipline DIAG cannot be used without z/VM > > > > > [ 260.626363] random: crng init done > > > > > qemu-system-s390x: terminating on signal 15 from pid 3815762 (timeout) > > > > > > > > > > We have a simple rootfs available if necessary: > > > > > > > > > > https://github.com/ClangBuiltLinux/boot-utils/raw/bc0d17785eb67f1edd0ee0a134970a807895f741/images/s390/rootfs.cpio.zst > > > > > > > > > > If there is any other information I can provide, please let me know! > > > > > > > > Hmm... strange. Can you please try the following command line options > > > > and tell me which of these has the issue and which don't? > > > > > > Sure thing! > > > > > > > 1) deferred_probe_timeout=0 > > > > > > No issue. > > > > > > > 2) deferred_probe_timeout=1 > > > > 3) deferred_probe_timeout=300 > > > > > > Both of these appear to hang in the same way, I let each sit for five > > > minutes. > > > > Strange that a sufficiently large timeout isn't helping. Is it trying > > to boot off a network mount? I'll continue looking into this next > > week. > > I don't think so, it seems like doing that requires some extra flags > that we do not have: > > https://wiki.qemu.org/Features/S390xNetworkBoot > > If you need any additional information or want something tested, please > let me know! I'll try to get qemu going on my end, but I'm not too confident I'll be able to get to it in a timely fashion. So if you can help figure out where this boot process is hanging, that'd be very much appreciated. Couple of suggestions for debugging: Can you add a log to "wait_for_device_probe()" and see if that's getting called right before the boot process hangs? If it does, can you get a stacktrace (I just add a WARN_ON(1) when I need a stack trace)? It's unlikely this is the case because deferred_probe_timeout=1 still causes an issue for you, but I'd be good to rule out. Let's try to rule out if deferred_probe_extend_timeout() is causing some issues. So, without my patch, what happens if you set: deferred_probe_timeout=1 deferred_probe_timeout=300 If deferred_probe_timeout=1 causes an issue even without my patch, then in addition, can you try commenting out the call to fw_devlink_drivers_done() inside deferred_probe_timeout_work_func() and try again? Thanks a lot for reporting and helping debug this issue. -Saravana 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 smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 689FEC433EF for ; Mon, 23 May 2022 20:04:47 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 25142416E9; Mon, 23 May 2022 20:04:46 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 12bEX1xbQrQT; Mon, 23 May 2022 20:04:44 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp4.osuosl.org (Postfix) with ESMTPS id B80F541296; Mon, 23 May 2022 20:04:43 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 9770AC0032; Mon, 23 May 2022 20:04:43 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [IPv6:2605:bc80:3010::137]) by lists.linuxfoundation.org (Postfix) with ESMTP id D75ACC002D for ; Mon, 23 May 2022 20:04:42 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id B04E6416DE for ; Mon, 23 May 2022 20:04:42 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id BZItXYpKp780 for ; Mon, 23 May 2022 20:04:40 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.8.0 Received: from mail-yb1-xb30.google.com (mail-yb1-xb30.google.com [IPv6:2607:f8b0:4864:20::b30]) by smtp4.osuosl.org (Postfix) with ESMTPS id 77FF141296 for ; Mon, 23 May 2022 20:04:40 +0000 (UTC) Received: by mail-yb1-xb30.google.com with SMTP id d137so27311994ybc.13 for ; Mon, 23 May 2022 13:04:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=u1AipD1OfrmQcB3YUOaC7P4EIOVqCxquxh0+AE+xuhM=; b=bQzOkbeNz00bM35Ce99+u6O7FvwcbMq3CbiwHzibWAm6u6rINPbk7M+Gwf+K9Rpfqf Bf403twpWA0WD0G/TeiGjK7xOqCHIbbjcEyaY7BokFUQ+zKuBOPZ4uuNji6TV8e8F0C1 OiSHL6d1UFbmnZn05rjy7t5aWkkhI9KCK9PlriUExXYqGdsnCTQfyAuJZt5YfiCD5x4p PKKVhF6lcNgu2psiwb4uusrHWD7/H5PDQpYT3YIO6SB5vgxXpWhixe5z1M+Sg7r5WGTG kStV8jBQu/gFdCpVP2vrKt9lgnlvuXrGHW8QBgL9FPZgCDY30zwKLwvPAhDhx3FPGx8x PsTQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=u1AipD1OfrmQcB3YUOaC7P4EIOVqCxquxh0+AE+xuhM=; b=efYIfyB6Q5oGIQ38GtH3wf6RHmQ9nU2cgdcm5sTfi9Mm1WApBNSlmRpd59cWbtUWer 3bm/itzY3QMBUe0dX6DNGbRFRTdcySC939rcZdUxRok8Zl7GwOBr/6+YE1RGizDZbiXT OQ4pJ4vvqO3eB9FlH1RdryWZMS682bWsmKmVW6Jz9arun7tZNRpvmOE0UrAUlsrLzhFn nMgj4y5JM0IkxZF9BrC2njzuVEG3E6q8vsC7kDTIYr96WDMzqqY+3D+nwiqJwJ1ZRNQt otsmaFXcNXPXJIrXh55sg80/6/T+26Sei4/tIGq2Qx1N9Ppc/7L+nzXDftFOCChx1au8 EqBQ== X-Gm-Message-State: AOAM530Zv5rrK76QJvFTYM0TV1/JIXs3vSoamnal4R4daTNPioBIpwUB xv8vLi1HEd16QQKuMzgUqG0qpt7Km3KN0QxwGsbRpA== X-Google-Smtp-Source: ABdhPJzqi3uJx736pHwpoReDWxmaiJiRfwvNOrYnqDbU07+DT5iV9p+v8KIvHm54c3ZBoXT3vDZcWATWAm//Q1iK/LY= X-Received: by 2002:a05:6902:70e:b0:64f:2e28:d64a with SMTP id k14-20020a056902070e00b0064f2e28d64amr23757981ybt.80.1653336279141; Mon, 23 May 2022 13:04:39 -0700 (PDT) MIME-Version: 1.0 References: <20220429220933.1350374-1-saravanak@google.com> In-Reply-To: Date: Mon, 23 May 2022 13:04:03 -0700 Message-ID: Subject: Re: [PATCH v1] driver core: Extend deferred probe timeout on driver registration To: Nathan Chancellor Cc: Ulf Hansson , linux-doc@vger.kernel.org, Linus Walleij , Pavel Machek , linux-s390@vger.kernel.org, Will Deacon , Rob Herring , Jonathan Corbet , "Rafael J. Wysocki" , Geert Uytterhoeven , Thierry Reding , kernel-team@android.com, linux-pm@vger.kernel.org, linux-gpio@vger.kernel.org, Mark Brown , Greg Kroah-Hartman , Kevin Hilman , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Paul Kocialkowski , iommu@lists.linux-foundation.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Saravana Kannan via iommu Reply-To: Saravana Kannan Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Mon, May 23, 2022 at 8:17 AM Nathan Chancellor wrote: > > On Fri, May 20, 2022 at 05:15:55PM -0700, Saravana Kannan wrote: > > On Fri, May 20, 2022 at 5:04 PM Nathan Chancellor wrote: > > > > > > On Fri, May 20, 2022 at 04:49:48PM -0700, Saravana Kannan wrote: > > > > On Fri, May 20, 2022 at 4:30 PM Nathan Chancellor wrote: > > > > > > > > > > Hi Saravana, > > > > > > > > > > On Fri, Apr 29, 2022 at 03:09:32PM -0700, Saravana Kannan wrote: > > > > > > The deferred probe timer that's used for this currently starts at > > > > > > late_initcall and runs for driver_deferred_probe_timeout seconds. The > > > > > > assumption being that all available drivers would be loaded and > > > > > > registered before the timer expires. This means, the > > > > > > driver_deferred_probe_timeout has to be pretty large for it to cover the > > > > > > worst case. But if we set the default value for it to cover the worst > > > > > > case, it would significantly slow down the average case. For this > > > > > > reason, the default value is set to 0. > > > > > > > > > > > > Also, with CONFIG_MODULES=y and the current default values of > > > > > > driver_deferred_probe_timeout=0 and fw_devlink=on, devices with missing > > > > > > drivers will cause their consumer devices to always defer their probes. > > > > > > This is because device links created by fw_devlink defer the probe even > > > > > > before the consumer driver's probe() is called. > > > > > > > > > > > > Instead of a fixed timeout, if we extend an unexpired deferred probe > > > > > > timer on every successful driver registration, with the expectation more > > > > > > modules would be loaded in the near future, then the default value of > > > > > > driver_deferred_probe_timeout only needs to be as long as the worst case > > > > > > time difference between two consecutive module loads. > > > > > > > > > > > > So let's implement that and set the default value to 10 seconds when > > > > > > CONFIG_MODULES=y. > > > > > > > > > > > > Cc: Greg Kroah-Hartman > > > > > > Cc: "Rafael J. Wysocki" > > > > > > Cc: Rob Herring > > > > > > Cc: Linus Walleij > > > > > > Cc: Will Deacon > > > > > > Cc: Ulf Hansson > > > > > > Cc: Kevin Hilman > > > > > > Cc: Thierry Reding > > > > > > Cc: Mark Brown > > > > > > Cc: Pavel Machek > > > > > > Cc: Geert Uytterhoeven > > > > > > Cc: Yoshihiro Shimoda > > > > > > Cc: Paul Kocialkowski > > > > > > Cc: linux-gpio@vger.kernel.org > > > > > > Cc: linux-pm@vger.kernel.org > > > > > > Cc: iommu@lists.linux-foundation.org > > > > > > Signed-off-by: Saravana Kannan > > > > > > > > > > I bisected a boot hang with ARCH=s390 defconfig in QEMU down to this > > > > > change as commit 2b28a1a84a0e ("driver core: Extend deferred probe > > > > > timeout on driver registration") in next-20220520 (bisect log below). > > > > > > > > > > $ make -skj"$(nproc)" ARCH=s390 CROSS_COMPILE=s390x-linux-gnu- defconfig bzImage > > > > > > > > > > $ timeout --foreground 15m stdbuf -oL -eL \ > > > > > qemu-system-s390x \ > > > > > -initrd ... \ > > > > > -M s390-ccw-virtio \ > > > > > -display none \ > > > > > -kernel arch/s390/boot/bzImage \ > > > > > -m 512m \ > > > > > -nodefaults \ > > > > > -serial mon:stdio > > > > > ... > > > > > [ 2.077303] In-situ OAM (IOAM) with IPv6 > > > > > [ 2.077639] NET: Registered PF_PACKET protocol family > > > > > [ 2.078063] bridge: filtering via arp/ip/ip6tables is no longer available by default. Update your scripts to load br_netfilter if you need this. > > > > > [ 2.078795] Key type dns_resolver registered > > > > > [ 2.079317] cio: Channel measurement facility initialized using format extended (mode autodetected) > > > > > [ 2.081494] Discipline DIAG cannot be used without z/VM > > > > > [ 260.626363] random: crng init done > > > > > qemu-system-s390x: terminating on signal 15 from pid 3815762 (timeout) > > > > > > > > > > We have a simple rootfs available if necessary: > > > > > > > > > > https://github.com/ClangBuiltLinux/boot-utils/raw/bc0d17785eb67f1edd0ee0a134970a807895f741/images/s390/rootfs.cpio.zst > > > > > > > > > > If there is any other information I can provide, please let me know! > > > > > > > > Hmm... strange. Can you please try the following command line options > > > > and tell me which of these has the issue and which don't? > > > > > > Sure thing! > > > > > > > 1) deferred_probe_timeout=0 > > > > > > No issue. > > > > > > > 2) deferred_probe_timeout=1 > > > > 3) deferred_probe_timeout=300 > > > > > > Both of these appear to hang in the same way, I let each sit for five > > > minutes. > > > > Strange that a sufficiently large timeout isn't helping. Is it trying > > to boot off a network mount? I'll continue looking into this next > > week. > > I don't think so, it seems like doing that requires some extra flags > that we do not have: > > https://wiki.qemu.org/Features/S390xNetworkBoot > > If you need any additional information or want something tested, please > let me know! I'll try to get qemu going on my end, but I'm not too confident I'll be able to get to it in a timely fashion. So if you can help figure out where this boot process is hanging, that'd be very much appreciated. Couple of suggestions for debugging: Can you add a log to "wait_for_device_probe()" and see if that's getting called right before the boot process hangs? If it does, can you get a stacktrace (I just add a WARN_ON(1) when I need a stack trace)? It's unlikely this is the case because deferred_probe_timeout=1 still causes an issue for you, but I'd be good to rule out. Let's try to rule out if deferred_probe_extend_timeout() is causing some issues. So, without my patch, what happens if you set: deferred_probe_timeout=1 deferred_probe_timeout=300 If deferred_probe_timeout=1 causes an issue even without my patch, then in addition, can you try commenting out the call to fw_devlink_drivers_done() inside deferred_probe_timeout_work_func() and try again? Thanks a lot for reporting and helping debug this issue. -Saravana _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu