From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=194.117.254.33 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792751272; b=Lrl2EQGmkiOpZwp4ulg80aZQ3edv/Leszz6DlP0XkI5/rcBKa568Cw0pya5y8Po70zQN KddVADga/HOAAnsU+9on3DIsFJk2IUxcDq2X0e6ycA1ktMD6i93DNIWIXnsrXYTee1Aab 5ugmuX+5C/rBR8rL7uQLSF75CQycGcKRpjRpRt4RRa2phZO8wB/grkHBl4HEhSQ1b+zL6 ZIKDTs3Mlwk9g0U5r+uHUPyT5PKN8Ct/w6tjYeu13YG3yd9fpsAWaXzhzgPCWwTRgPUqF hxryv5uCOSZzFyC+5VtEa3b4p2GEBj6lHtJAdlMw7BWeziy05xoAQbqRH14q7yJu2Rw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792751272; h=DMARC-Filter:DKIM-Signature:Received:Received:X-UD-Smtp-Session:Date: From:To:Cc:Subject:Message-ID:References:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; bh=qZ4/eiHVwBullnoqGWKFL11/mhEiAdGloLPRwlR6r+8=; b=dORPJV6q2IM9c8OeHf7c5wrPP4OPhaHxEUZoK1OPiemvteiSFg0DtWqR0s7cQgpcqVln 629UqPrNN4vD7YpTqnfLWqiNfu5lDRdnoyaY5Gov9r2jydhr9AEaSFQlhuRBCI3R9Cm/8 ChEY0XtlUViYrAZms/8JETBXiB9gCdSxElkL7lDhxlOTJj0ZDpmEtTeXsopsglJrX6DiL EEuftI+NgqF1inwm+TWX1nKZe34HCh1DxIkl6+CoH9wx+gDJCEMwRdswbveWe9pry04Dt uGccbmTuj92aKFRdFVDZSmPVuw5kgcmiHTA0z0fqkWUSg5sdwPY9B8ppbWSN+NCZ/tQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none header.from=sang-engineering.com; spf=pass smtp.mailfrom=sang-engineering.com; dkim=pass header.d=sang-engineering.com header.i=@sang-engineering.com header.a=rsa-sha256 header.s=k1 header.b=ZbIMhIhr; arc=none smtp.remote-ip=194.117.254.33 Received: from mail.zeus03.de (zeus03.de [194.117.254.33]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 67E9B606A323 for ; Fri, 23 Oct 2026 10:27:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 67E9B606A323 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sang-engineering.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sang-engineering.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=sang-engineering.com header.i=@sang-engineering.com header.a=rsa-sha256 header.s=k1 header.b=ZbIMhIhr DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= sang-engineering.com; h=date:from:to:cc:subject:message-id :references:mime-version:content-type:in-reply-to; s=k1; bh=qZ4/ eiHVwBullnoqGWKFL11/mhEiAdGloLPRwlR6r+8=; b=ZbIMhIhrgXZDuqu2lwwb 5iRvKSTpxPy5LvrOUvYWWXaMTT1Fv5ibgEYanyUX3uSns+/xJef3M0xY1Oci9hHg wZKWD9rq1XzxK/dHN1WJ/ZBauju7E8i4IMyTpYfn77fstXsYdENGLrhPBGAT4AFO 9DWeyYkdSVRPcJ4xUjjxGG7l85bMTL+KwoKM1YWh1e/bBrcCVz3JljNqddvRUyfS y/APWvsW9z91/yPFZ8ZJYwC3Z3aEFtcpsy+OgYYzTDITYsrV4MXeC328y6SiyqWi f2MtDePfCTR5mYbi07eUSoh/wL5b38GAdSOYAR09wRF95l2NfumKL8+yMk2vejs9 7g== Received: (qmail 1512031 invoked from network); 23 Oct 2026 12:27:42 +0200 Received: by mail.zeus03.de with ESMTPSA (TLS_AES_256_GCM_SHA384 encrypted, authenticated); 23 Oct 2026 12:27:42 +0200 X-UD-Smtp-Session: l3s3148p1@oDMgbn9eTKYujnv2 Date: Fri, 23 Oct 2026 12:27:41 +0200 From: Wolfram Sang To: Diogo Ivo Cc: Tommaso Merciai , Alexandre Belloni , Frank Li , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Geert Uytterhoeven , Magnus Damm , Stephen Boyd , Brian Masney , Jerome Brunet , Linus Walleij , linux-i3c@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH 1/8] i3c: renesas: Fix zero I2C SCL rate on pure I3C buses Message-ID: References: <20261020-divo-ssgrlpcsrc-2966-i3c-v1-0-30a47f25e515@renesas.com> <20261020-divo-ssgrlpcsrc-2966-i3c-v1-1-30a47f25e515@renesas.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261020-divo-ssgrlpcsrc-2966-i3c-v1-1-30a47f25e515@renesas.com> On Tue, Oct 20, 2026 at 10:14:55AM +0100, Diogo Ivo wrote: > On a pure I3C bus there are no I2C devices, so the I3C core leaves > bus->scl_rate.i2c at zero if i2c-scl-hz is not specified in DT. > Deriving i2c_total_ticks from that zero rate programs a zero-width > open-drain SCL into the STDBR open-drain fields, which are still used > in pure I3C mode for example in DAA. > > Fall back to the 1 MHz FM+ limit instead, the fastest rate an I2C > device could have, so that a sane open-drain timing is programmed. > > Fixes: d028219a9f14 ("i3c: master: Add basic driver for the Renesas I3C controller") > Cc: stable@vger.kernel.org > Signed-off-by: Diogo Ivo Great catch! Kudos for adding a good comment. I agree with Geert about using the ternary operator, though. After that, you can add my: Reviewed-by: Wolfram Sang