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 9B4DAC433FE for ; Mon, 3 Oct 2022 16:36:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229879AbiJCQgM (ORCPT ); Mon, 3 Oct 2022 12:36:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229827AbiJCQgL (ORCPT ); Mon, 3 Oct 2022 12:36:11 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C3DF7248FF for ; Mon, 3 Oct 2022 09:36:09 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 862D8B81085 for ; Mon, 3 Oct 2022 16:36:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 09561C433D6; Mon, 3 Oct 2022 16:36:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664814967; bh=ccW+tkWSElZlxhcfUKcBl7RsYL1qCVl94H7TGENvxYM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=G1cVCUNiJsfUQm7UxCFkUzHqAUk9PgY0TzsgOhQVnwCspkPBNe8qeBOXPNJf6XlXY iWSpAAyHUSlhoobqbln/Dz7WG2o6Y3ukaExZSp19ixW8ZkAgkPwIU5/2/OY+s0JaOe pfZA4w7KXl3cHJsJCpqHS/Cg0STrMyRDYxdna8Xbcno1PCjeqUdv50KEI8oqgMLNPE PE7rsO5mKe5jisJ8ZZyaeOBcN7yuO1Elq5cjLOqnk6IGwGkZCmP3+JwDgjcsp01OhF n4mpBF/YElfVpQgOcRzUaewJhbzJ8a8exJYN+nk1asSeoBGyACG7lQg2vO4dkOdNo8 B3dTEfENPHZng== Date: Mon, 3 Oct 2022 09:36:06 -0700 From: Jakub Kicinski To: Uwe =?UTF-8?B?S2xlaW5lLUvDtm5pZw==?= , Douglas Miller Cc: netdev@vger.kernel.org, Greg Kroah-Hartman , "Rafael J. Wysocki" , kernel@pengutronix.de, "Guilherme G. Piccoli" Subject: Re: Strangeness in ehea network driver's shutdown Message-ID: <20221003093606.75a78f22@kernel.org> In-Reply-To: <20221001143131.6ondbff4r7ygokf2@pengutronix.de> References: <20221001143131.6ondbff4r7ygokf2@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sat, 1 Oct 2022 16:31:31 +0200 Uwe Kleine-K=C3=B6nig wrote: > Hello, >=20 > while doing some cleanup I stumbled over a problem in the ehea network > driver. >=20 > In the driver's probe function (ehea_probe_adapter() via > ehea_register_memory_hooks()) a reboot notifier is registered. When this > notifier is triggered (ehea_reboot_notifier()) it unregisters the > driver. I'm unsure what is the order of the actions triggered by that. > Maybe the driver is unregistered twice if there are two bound devices? > Or the reboot notifier is called under a lock and unregistering the > driver (and so the devices) tries to unregister the notifier that is > currently locked and so results in a deadlock? Maybe Greg or Rafael can > tell about the details here? >=20 > Whatever the effect is, it's strange. It makes me wonder why it's > necessary to free all the resources of the driver on reboot?! I don't > know anything about the specifics of the affected machines, but I guess > doing just the necessary stuff on reboot would be easier to understand, > quicker to execute and doesn't have such strange side effects. >=20 > With my lack of knowledge about the machine, the best I can do is report > my findings. So don't expect a patch or testing from my side. Last meaningful commit to this driver FWIW: commit 29ab5a3b94c87382da06db88e96119911d557293 Author: Guilherme G. Piccoli Date: Thu Nov 3 08:16:20 2016 -0200 Also that's the last time we heard from Douglas AFAICT..