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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,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 D6C81C47098 for ; Fri, 4 Jun 2021 00:42:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B9A81613F3 for ; Fri, 4 Jun 2021 00:42:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229867AbhFDAoE (ORCPT ); Thu, 3 Jun 2021 20:44:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36838 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229576AbhFDAoE (ORCPT ); Thu, 3 Jun 2021 20:44:04 -0400 Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CBE8FC06174A; Thu, 3 Jun 2021 17:42:18 -0700 (PDT) Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4Fx3r76hVPz9s24; Fri, 4 Jun 2021 10:42:15 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ellerman.id.au; s=201909; t=1622767336; bh=DQpYo9q9ZGmy3/Mz9ZsYTiA+IvTCwyCbRWUrvMTeOWg=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=XCSoOX7+qd0hTsKT5E44LzCwxhYBrifdK2aZAP+aS3g3Jkr2lirTl4yXlsasbfpV1 0NIqKavfSaGn/V+8EA0FmH3rpG5eBR/UWn8HJbjnpvWY/crHolu/n65SJNszrhRk/+ 9oJBMq6EJweWntk3gTnGz6NKGowoEF6BTLyFOvshwr+/a6sIqEhABPUf9OMcEQ8S2i 2nN5ebs9M1/7a8fUFX/ceCS9JoCRZostRS311xpHia8fHEwiagVGDzFUtNTTX0BZVm 3B09zc7XiTN3lI4OUQBhZGBiDzvcF6LIjC7fbXiQgdcoSqlLaiD8WW69Sx6NzYQLuR v2gUjE0842asw== From: Michael Ellerman To: Sasha Levin , linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Chris Packham , Wolfram Sang , Sasha Levin , 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 In-Reply-To: <20210603170734.3168284-42-sashal@kernel.org> References: <20210603170734.3168284-1-sashal@kernel.org> <20210603170734.3168284-42-sashal@kernel.org> Date: Fri, 04 Jun 2021 10:42:15 +1000 Message-ID: <87y2bqfok8.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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") 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. 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. cheers > diff --git a/arch/powerpc/boot/dts/fsl/p2041si-post.dtsi b/arch/powerpc/boot/dts/fsl/p2041si-post.dtsi > index 872e4485dc3f..ddc018d42252 100644 > --- a/arch/powerpc/boot/dts/fsl/p2041si-post.dtsi > +++ b/arch/powerpc/boot/dts/fsl/p2041si-post.dtsi > @@ -371,7 +371,23 @@ sdhc@114000 { > }; > > /include/ "qoriq-i2c-0.dtsi" > + i2c@118000 { > + fsl,i2c-erratum-a004447; > + }; > + > + i2c@118100 { > + fsl,i2c-erratum-a004447; > + }; > + > /include/ "qoriq-i2c-1.dtsi" > + i2c@119000 { > + fsl,i2c-erratum-a004447; > + }; > + > + i2c@119100 { > + fsl,i2c-erratum-a004447; > + }; > + > /include/ "qoriq-duart-0.dtsi" > /include/ "qoriq-duart-1.dtsi" > /include/ "qoriq-gpio-0.dtsi" > -- > 2.30.2