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 9AF39CA0FE4 for ; Fri, 1 Sep 2023 17:03:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231557AbjIARD6 (ORCPT ); Fri, 1 Sep 2023 13:03:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56286 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230254AbjIARD5 (ORCPT ); Fri, 1 Sep 2023 13:03:57 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7514210F2 for ; Fri, 1 Sep 2023 10:03:54 -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 30E5F1F853; Fri, 1 Sep 2023 17:03:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1693587833; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9GagGRztP1T820hQctp2gZEuFFiWxTmDDCxtH5A4stY=; b=ldkiK20Acr0LYaoHhgSeFQZ+Qat22kxQY//5ly0PfcrJqzt8Lc4oJXPTU1c5ck6LVH4wOT OTEuCNYoLCfL2tMoDIM9qE1pG5H370lRW5ZQoTkFaq9ekd+zjmIr//FoapDc6L+QQh14pZ 7xHKUjtdGSwAfNp1fexizoNxS2fOWaY= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1693587833; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9GagGRztP1T820hQctp2gZEuFFiWxTmDDCxtH5A4stY=; b=sI/KRgGRyMsk1K4ar7Zkgc05YQiAvIAkimxoqVJbK2236Mo08h6fBye2S6MFCdaLgRCKl7 kQ5AW3u20qA2CNDQ== 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 0409A1358B; Fri, 1 Sep 2023 17:03:52 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id +Lv7OXgZ8mRyLAAAMHmgww (envelope-from ); Fri, 01 Sep 2023 17:03:52 +0000 Date: Fri, 1 Sep 2023 19:03:51 +0200 From: Jean Delvare To: Heiner Kallweit Cc: Andi Shyti , linux-i2c@vger.kernel.org Subject: Re: [PATCH] i2c: i801: fix cleanup code in remove() and error path of probe() Message-ID: <20230901190351.2bd3b346@endymion.delvare> In-Reply-To: References: <07386d35-0f9f-bcd7-185c-d8eed60fc794@gmail.com> <20230901141929.640fc5d5@endymion.delvare> Organization: SUSE Linux X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.34; x86_64-suse-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org On Fri, 1 Sep 2023 14:41:38 +0200, Heiner Kallweit wrote: > On 01.09.2023 14:19, Jean Delvare wrote: > > On Sun, 27 Aug 2023 22:26:05 +0200, Heiner Kallweit wrote: > >> Jean pointed out that the referenced patch resulted in the remove() > >> path not having the reverse order of calls in probe(). I think there's > >> more to be done to ensure proper cleanup. > >> Especially cleanup in the probe() error path has to be extended. > >> Not every step there may be strictly needed, but it's in line with > >> remove() now. > >> > >> Fixes: 9b5bf5878138 ("i2c: i801: Restore INTREN on unload") > > > > I think it also fixes 9424693035a5 ("i2c: i801: Create iTCO device on > > newer Intel PCHs"). > > Right. We should add this, even though this fix won't apply cleanly > on some older kernel versions. I think we'll need separate patches for these > LTS kernel versions. Our task is to annotate the commit message with the dependency information. Whether or not people want to backport the fix to a given kernel is their decision. Personally I wouldn't bother backporting this to stable kernels, as it's not "a real bug that bothers people", to quote Documentation/process/stable-kernel-rules.rst. > >> Cc: stable@vger.kernel.org > >> Signed-off-by: Heiner Kallweit > >> --- > >> drivers/i2c/busses/i2c-i801.c | 14 ++++++++------ > >> 1 file changed, 8 insertions(+), 6 deletions(-) > >> > >> diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c > >> index 73ae06432..7a0ccc584 100644 > >> --- a/drivers/i2c/busses/i2c-i801.c > >> +++ b/drivers/i2c/busses/i2c-i801.c > >> @@ -1754,6 +1754,9 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id) > >> "SMBus I801 adapter at %04lx", priv->smba); > >> err = i2c_add_adapter(&priv->adapter); > >> if (err) { > >> + platform_device_unregister(priv->tco_pdev); > >> + outb_p(priv->original_hstcnt, SMBHSTCNT(priv)); > > > > Doesn't seem to be needed, as I can't see SMBHSTCNT being written to > > during probe? > > > Right, this is what I was referring to in the commit message when saying > "not every step may be strictly needed". Restoring SMBHSTCNT isn't needed Oh right, missed that, sorry. > here, but it makes cleanup in the probe error path the same as in remove > and therefore may improve readability and maintainability. > But I don't insist on it and don't have a strong opinion. I think it would make sense to omit it from the probe error path (to make it clear it's not needed there) and move it at the end of i801_remove() and i801_shutdown(). That way the probe error path is still a subset of the remove and shutdown paths and I think this solves the maintainability issue. Would that be OK with you? -- Jean Delvare SUSE L3 Support