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 C0F34C433F5 for ; Thu, 9 Dec 2021 09:22:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235946AbhLIJZg (ORCPT ); Thu, 9 Dec 2021 04:25:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46574 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235674AbhLIJZc (ORCPT ); Thu, 9 Dec 2021 04:25:32 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0F942C0617A2; Thu, 9 Dec 2021 01:21:59 -0800 (PST) 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 sin.source.kernel.org (Postfix) with ESMTPS id 429C0CE245E; Thu, 9 Dec 2021 09:21:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A8726C004DD; Thu, 9 Dec 2021 09:21:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1639041715; bh=TEW0W8Vu/yqwzKooRUV6+GpDbQd/xLe/GfTkTMDyE1s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=aw272oV2rTjAhb/s/AjSgGQvqT0bTivpqlMMijQlv9vBUEpgiZ3V4zSSaLSMBa7Kn MPDZ7aSoUqYwKhZCsjOQH1Yh4bg4HREFsWsBisfTwYGQK5OIfWY8loFIOl0Qlcv5N5 GkdcfC/rs8xr3zpAQ2tYqV3853zV2hshEWoRmFLuDzxj5WhylaSN059EsCyPQj5mLP BlFGOcmeAazAP3xeb7fphsTMwy8CEccjAurtnnxIDIHJOFdH/AwynnicpaOz2SPJvL oK2S5l3wGt9ePT55/O2AtnnSP/MxcgXk+1jGkyF4zrl4s7OwNKryO6ESEhmk4Ka6tX EmLchwbYVv4Pw== Date: Thu, 9 Dec 2021 10:21:52 +0100 From: "wsa@kernel.org" To: Chris Packham Cc: "mbizon@freebox.fr" , "linux-i2c@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] i2c: mpc: Use atomic read and fix break condition Message-ID: Mail-Followup-To: "wsa@kernel.org" , Chris Packham , "mbizon@freebox.fr" , "linux-i2c@vger.kernel.org" , "linux-kernel@vger.kernel.org" References: <20211207042144.358867-1-chris.packham@alliedtelesis.co.nz> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="C9A6rRvoZs0n2wPQ" Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --C9A6rRvoZs0n2wPQ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > we'd hit the 100us timeout in the poll). But I see no evidence of that=20 > actually happening (and no idea what arbitration lost means w.r.t i2c). On a bus with multiple masters, it means the other master has won the arbitration because the address it wants to talk to contains more 0 bits. > I don't know that there is a maximum clock stretch time (we certainly=20 > know there are misbehaving devices that hold SCL low forever). The SMBUS= =20 > protocol adds some timeouts but as far as I know i2c says nothing about= =20 > how long a remote device can hold SCL. The above is all correct. Even with the unclear situation about the 100us, I think this should go to for-current soon, right? --C9A6rRvoZs0n2wPQ Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAmGxyrAACgkQFA3kzBSg KbZrXBAAg4dz1LsvbcnmNyLdQ66iPTmRYU4o/47hytTcVFB9SVW+gPicn1qJEBrU 5uLvqoFE8qrpOVRgXkSr3cCu4XkgX+QXGbroAI9W44l8e8806N5N9/Xv8uOgtAcE eTs5Zlzx8b8gpHTkd2WnrNe7/0A9udZ9lNBibD5/ChFDvCpEf1lmd5AIYRZDkLJl AqChjdMYiNg/GJHV9cwa/tuw6dPjoh/QVax1elfpcTkH3YgRZrsxgZAEiDth9otS XdyBUendnikHV/ItwPq8z+a/9+hHyeBCKoMBLdCXEya53l/OvnyvsMLO8jSYlDMK 6/8VzMTPkYAu70DZEV9pxAA+f0bi7mvUZ1goEUfCtvvDJHybdhRjh8Hzq5xf5KJV u9b6ty+b4k6P/9+ewLmvs7pDIbopnviyL8gh97HJD2IhfAGRNXvQwPumLfE/oWWW Z0eEzWFOM8gqm1PMaLTL+7I3z0CodQdNvGvnKRD4iXfwJB2gD7qQ9ktdg2ps4WnS 8s9GUSV01fQ3k7hFYgRooRgD+fu5OPFsXrzvMMiy9geW0DcVrLfsPfW5UNfJ9fbL aQyN7Zw8sB6aUZ7dCUw5mdUhifm4hf6Oftm2PZtAkA/jpq0j1AN0DWSljqT4BR94 Be64hVANbI10bPu1FxdYg/na64RUHLS4YwpeJUu/ic1rpM2NqVQ= =t+mF -----END PGP SIGNATURE----- --C9A6rRvoZs0n2wPQ--