From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 83BCE606A31B for ; Fri, 23 Oct 2026 10:27:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=rdcVr4ep; dkim=fail reason="signature verification failed" (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; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; 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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-Archived-By: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20261020-divo-ssgrlpcsrc-2966-i3c-v1-1-30a47f25e515@renesas.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261023_032749_416286_239CEB10 X-CRM114-Status: GOOD ( 10.70 ) X-Spam-Score: -2.1 (--) X-BeenThere: linux-i3c@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-i3c" X-Spam-Status: No, score=-9.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 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 -- linux-i3c mailing list linux-i3c@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-i3c