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[2604:1380:4601:e00::3]) by mx.google.com with ESMTPS id r9-20020a1709060d4900b00a52264031e5si7242845ejh.169.2024.04.23.09.46.37 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Apr 2024 09:46:37 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel+bounces-155592-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3; Authentication-Results: mx.google.com; dkim=neutral (body hash did not verify) header.i=@kernel.org header.s=k20201202 header.b="VW//JClN"; arc=fail (body hash mismatch); spf=pass (google.com: domain of linux-kernel+bounces-155592-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) smtp.mailfrom="linux-kernel+bounces-155592-linux.lists.archive=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by am.mirrors.kernel.org (Postfix) with ESMTPS id C89D71F26842 for ; Tue, 23 Apr 2024 16:46:36 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3CA3013D606; Tue, 23 Apr 2024 16:46:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VW//JClN" Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 540DB13BAFE; Tue, 23 Apr 2024 16:46:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713890783; cv=none; b=kkBhFmw9sPV7PhTB8wRCr8mtsOKSByE+qSy0b4jrHz8zB0EYFRO69wRztm0PgSm17oyOw0G2htudPCqwPuaf+q4wLdH7wgbcrjZJH31je/4IvSbQfVLJE46yJmYCWFrdLzTBv3b69/8cRd8k80HQ0qPZNM6FhmgzsJZ6BgMuelI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713890783; c=relaxed/simple; bh=d6fUPT7FccaSpbhAaWt+3bXIMJB6KRIJ6QO0yTnP038=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=E1wdi2Q7BalRVecUMmUqZ0fkaVp1/OvjomuiH/g+dOYkcbI6WTPr+nWkdhzVbTfp2bjlTKiYxnQ9eXQr2XpcIsvcCJUaBRt949AyVZ4o0+xlID64kVfn+18Mn6Uh9vI2rqxcZAsU3Wsmxe79N9qEcWo5bH357BMDMzU8r1ci+38= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VW//JClN; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 17428C116B1; Tue, 23 Apr 2024 16:46:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713890782; bh=d6fUPT7FccaSpbhAaWt+3bXIMJB6KRIJ6QO0yTnP038=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VW//JClNLBdywVje2WU6TgzA/sd6UIAiscV0HlVXGhCD19BwZG5atbmQRH/qm/nMf RwrIAGS3M9LGnI0rin3JJ9NWKsj6cnXpz1Pz6mCvIt1DfZWVCuV4g6M1TIEm9QS5UY Kp5tywStDs1+ph8qr4NtIaXuGZt4Qvunna7FwICtBvvawtEhce117pR7iPrGZEJDz/ xQJ9brNKx+1Vwo3iL/HXTIqx4ZwvlxHevJ99ais6v96nvBgiE9C3kEgMc04ESDP1Gl 3fuxPXMiS4FqJGZ1mBIwyG8yLUzHSfVVXhZDlQ0PC6HHb9TWpRUM1M6bFdqhdZpvRp KXWAIDcrJkWPw== Date: Tue, 23 Apr 2024 17:46:16 +0100 From: Simon Horman To: Gregor Herburger Cc: Marc Kleine-Budde , Manivannan Sadhasivam , Thomas Kopp , Vincent Mailhol , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Rob Herring , Krzysztof Kozlowski , Conor Dooley , linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux@ew.tq-group.com, alexander.stein@ew.tq-group.com Subject: Re: [PATCH 2/4] can: mcp251xfd: mcp251xfd_regmap_crc_write(): workaround for errata 5 Message-ID: <20240423164616.GX42092@kernel.org> References: <20240417-mcp251xfd-gpio-feature-v1-0-bc0c61fd0c80@ew.tq-group.com> <20240417-mcp251xfd-gpio-feature-v1-2-bc0c61fd0c80@ew.tq-group.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240417-mcp251xfd-gpio-feature-v1-2-bc0c61fd0c80@ew.tq-group.com> On Wed, Apr 17, 2024 at 03:43:55PM +0200, Gregor Herburger wrote: > According to Errata DS80000789E 5 writing IOCON register using one SPI > write command clears LAT0/LAT1. > > Errata Fix/Work Around suggests to write registers with single byte write > instructions. However, it seems that every write to the second byte > causes the overrite of LAT0/LAT1. nit: overwrite Flagged by ./scripts/checkpatch.pl --codespell > > Never write byte 2 of IOCON register to avoid clearing of LAT0/LAT1. > > Signed-off-by: Gregor Herburger ..