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 X-Spam-Level: X-Spam-Status: No, score=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D411C48BE0 for ; Thu, 10 Jun 2021 22:00:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 71515613F1 for ; Thu, 10 Jun 2021 22:00:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230365AbhFJWCh (ORCPT ); Thu, 10 Jun 2021 18:02:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:58508 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229941AbhFJWCf (ORCPT ); Thu, 10 Jun 2021 18:02:35 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 77667613F1; Thu, 10 Jun 2021 22:00:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623362438; bh=nucnG5/QbJ/UafKRCt55CqTzS6+sHQTAWpyRcFUheUY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OKDp/WO/2bZ7+KuIi5wq/GKNwZymdnRr5mMC5N4kLONwm3q39r4C4LUf0oS0wvBhK wGZxbu1b58cfY8QfKIKVwwWNH2snT2EWNjbsSznxKJmHA/RsXHqMHouhk6RcTldiQF d5QWj/ZQ3ui5F753H6wYJvaiAdlEMknnlA5SfAOEHuVMY9Q4YTHwJINXKZllTZkqXX BDR5ikIdLCN3cjPGA0KoHgMdewY3wDN7MV8lK98ML37yKwzsXzcLfhKpr55W2hHULT IGXttB4srUQLbSSyM6t7wNaJtdAZWPAhnX8gthnHxr5yQUXVAmumx0g78UPruQGNWC oLfODFtKbYMHA== Date: Thu, 10 Jun 2021 18:00:37 -0400 From: Sasha Levin To: Chris Packham Cc: Michael Ellerman , "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" , Wolfram Sang , "devicetree@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" Subject: Re: [PATCH AUTOSEL 5.12 42/43] powerpc/fsl: set fsl,i2c-erratum-a004447 flag for P2041 i2c controllers Message-ID: References: <20210603170734.3168284-1-sashal@kernel.org> <20210603170734.3168284-42-sashal@kernel.org> <87y2bqfok8.fsf@mpe.ellerman.id.au> <81ce50f1-73eb-687b-898a-df5f6ac68c5a@alliedtelesis.co.nz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <81ce50f1-73eb-687b-898a-df5f6ac68c5a@alliedtelesis.co.nz> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 04, 2021 at 12:58:54AM +0000, Chris Packham wrote: > >On 4/06/21 12:42 pm, Michael Ellerman wrote: >> Sasha Levin writes: >>> From: Chris Packham >>> >>> [ Upstream commit 7adc7b225cddcfd0f346d10144fd7a3d3d9f9ea7 ] >>> >>> The i2c controllers on the P2040/P2041 have an erratum where the >>> documented scheme for i2c bus recovery will not work (A-004447). A >>> different mechanism is needed which is documented in the P2040 Chip >>> Errata Rev Q (latest available at the time of writing). >>> >>> Signed-off-by: Chris Packham >>> Acked-by: Michael Ellerman >>> Signed-off-by: Wolfram Sang >>> Signed-off-by: Sasha Levin >>> --- >>> arch/powerpc/boot/dts/fsl/p2041si-post.dtsi | 16 ++++++++++++++++ >>> 1 file changed, 16 insertions(+) >> This patch (and the subsequent one), just set a flag in the device tree. >> >> They have no effect unless you also backport the code change that looks >> for that flag, which was upstream commit: >> >> 8f0cdec8b5fd ("i2c: mpc: implement erratum A-004447 workaround") > >That change itself isn't cherry-pick able without > >65171b2df15e ("i2c: mpc: Make use of i2c_recover_bus()") > >and in between 65171b2df15e and 8f0cdec8b5fd are a bunch of cleanups and >a fairly major rewrite which may also affect the cherry-pick ability. > >> AFAICS you haven't picked that one up for any of the stable trees. >> >> I'll defer to Chris & Wolfram on whether it's a good idea to take the >> code change for stable. > >We have been doing some extra QA on our end for the "i2c: mpc: Refactor >to improve responsiveness" and "P2040/P2041 i2c recovery erratum" series >which hasn't thrown up any issues. But it's still a lot of new code and >at some point we're going to run into API changes. > >Given the fact that it's starting to snowball one might err on the side >of caution. > >> I guess it's harmless to pick these two patches, but it's also >> pointless. So I think you either want to take all three, or drop these >> two. > >At a minimum you need > >65171b2df15e ("i2c: mpc: Make use of i2c_recover_bus()") >8f0cdec8b5fd ("i2c: mpc: implement erratum A-004447 workaround") >7adc7b225cdd ("powerpc/fsl: set fsl,i2c-erratum-a004447 flag for P2041 >i2c controllers") >19ae697a1e4e ("powerpc/fsl: set fsl,i2c-erratum-a004447 flag for P1010 >i2c controllers") I'll take the two additional commits, thanks! -- Thanks, Sasha