From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bg1.exmail.qq.com (bg1.exmail.qq.com [114.132.77.159]) (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 81B891F4611; Fri, 27 Mar 2026 07:06:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.132.77.159 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774595195; cv=none; b=Ar1vt94nciWmjSuM4NuujWoD5pAysTHznMixZE/Do8MMdDc4smXk1TTT54abPiSLJHzmGojvDbSq/+siaVlGVhsfO0yo3d1bYQINHkva9BWTkThCwE2YCbdIf5M6ypwWZ6zQAs0TcPPuBWdFxxnptSp6Sd6ziocpCoz/G1fOxqY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774595195; c=relaxed/simple; bh=acJnhk3DhlEkQc4Hdu9XGurQ2f/IqUWKVh1uoABR9WA=; h=Mime-Version:Content-Type:Date:Message-Id:Cc:Subject:From:To: References:In-Reply-To; b=hheAZxiareWUERUpedmCi3UjbwkiylxRckLF4PJyRdAjm8B3nIcohezEnehm+42Twq8WFMkXHplXXRatzFzNDlFVoQo65Ou8HFs90feI/sQMy9wG+AtKlnXjxvczVSeEuIdKtCBXdQEo2aFxZsweUsGSqqfJauUIPYjSaFK3Vyc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux.spacemit.com; spf=none smtp.mailfrom=linux.spacemit.com; dkim=pass (1024-bit key) header.d=linux.spacemit.com header.i=@linux.spacemit.com header.b=oJT4MR45; arc=none smtp.client-ip=114.132.77.159 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux.spacemit.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.spacemit.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.spacemit.com header.i=@linux.spacemit.com header.b="oJT4MR45" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.spacemit.com; s=mxsw2412; t=1774595091; bh=C5sPPhxc2ESUsfKZcmePqfZSGtd39KSgY9EBT4h19Z4=; h=Mime-Version:Date:Message-Id:Subject:From:To; b=oJT4MR45zGFsDiQoi7e3V7hweAfxTuleEh3YMiT8E1pJVzLnTy7gQkvT3j/L9hsBT 8hOTgyJ3jYWn8Snir6f6LKegADFzc6U8jLNeX1bOOYZg5wbx4a2oQwhFloMOjjkgl8 dQsJpnoncULL7vYfFXAsEaGIh18sbWqT0gY9dWAI= X-QQ-mid: zesmtpsz9t1774595088tae86de95 X-QQ-Originating-IP: w/WyDemxcbjpJuaCt1YW/wsPI2c2ZYwcqhNJMRnh9EA= Received: from = ( [120.237.158.181]) by bizesmtp.qq.com (ESMTP) with id ; Fri, 27 Mar 2026 15:04:46 +0800 (CST) X-QQ-SSF: 0000000000000000000000000000000 X-QQ-GoodBg: 0 X-BIZMAIL-ID: 1752965271814094096 EX-QQ-RecipientCnt: 21 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Fri, 27 Mar 2026 15:04:46 +0800 Message-Id: Cc: "Rob Herring" , "Krzysztof Kozlowski" , "Conor Dooley" , "Paul Walmsley" , "Palmer Dabbelt" , "Albert Ou" , "Alexandre Ghiti" , "Yixun Lan" , "Vinod Koul" , "Frank Li" , "Guodong Xu" , "Michael Turquette" , "Stephen Boyd" , , , , , , Subject: Re: [PATCH v2 2/7] dt-bindings: dmaengine: Add SpacemiT K3 DMA compatible string From: "Troy Mitchell" To: "Conor Dooley" , "Troy Mitchell" X-Mailer: aerc 0.21.0-0-g5549850facc2 References: <20260326-k3-pdma-v2-0-ca94ca7bb595@linux.spacemit.com> <20260326-k3-pdma-v2-2-ca94ca7bb595@linux.spacemit.com> <20260326-explode-surplus-24c0e0813099@spud> In-Reply-To: <20260326-explode-surplus-24c0e0813099@spud> X-QQ-SENDSIZE: 520 Feedback-ID: zesmtpsz:linux.spacemit.com:qybglogicsvrgz:qybglogicsvrgz3a-0 X-QQ-XMAILINFO: McJfg7Aee/FZuqgBLJa/xaD93ptxSj5gtrQRlr2BHMhaSuQ7Hmc7FSVm nIbSM/Gn9ozMbLDAzyDH+vq5F/k9zjNFar+BG0Flj5Fv5Qb3kLBOQgep/HUvaEWm+0REQgk utQdzLZlWXNyZv2nn0GyzOdluz6WiLSYfnDkvmLzrjDA1IDE7LTjtyNcunyenvlBbjYaBL7 mEa7uvvsPio6wr4K+A8wHylXqbN1xA5Omj74pPKdJ+wtE1q9+WC3rVp1Ss5BsRB8d2ghPly NbCS9jz/nQTk4C2cOLP4oNcXZ+C7rrA3EYWGj3tICHboN6UMAl1rPf7fA6NKoqLBaPD6a6E b8X62kTE4p8pepTCHO0caY5TYjyPWGFznU+M06CCNS9yzqWnErMdhJQ0Pdnr5gazRMTq+kj bnz6JW7yTTJ0OBaE2grKZjRUb5XfmfCOPkzi6RQoXsJ34mtxevGQKnXfUufsCCM+TasNNYF bmlQf+G7vCOo+Rt952DsFtLZt4xuH05ppyLSgnFQOjXzZoj3TKEj6EOfwrfnivwaDImWGpm twhLEFYC552lvFErafayaB9W64nfLbRea2jgYNRNxNK5sckvJ7IXERvCT9xDZXp2JkrZ9Zb jqB9h5NezcuFHQzSd92GpEx4yB/mqPX325JDsllEaoxHm9z8tEJ1YK3mSklNr67A943Uze0 /Q/lTzNybK/WbckQe+DCVkk7TxkHPwmGxNgNiMgH8lSBQnZ+tTJKbnK8L+G8dDgusUS6Fps CIhnSCyOr1nlHKL/tWEwK2sBNzt6DfcW4XD37Cv9CTWqQgyThhGlnVSSivvBYDqR7pOlC9V herj0wt6QAME/Q62DeFPxjHm17xsYWWc9J2Eo8WvZYcI0n2BCp+4lN9f7mebQTwbtq/QSrg uzgfBsa5kTO7UaFg/BDsF3Ye+YSMuI7L7nG0z6YKHWVrcOUa2Ni5leJnuDmxQb7EAaY9Slv t0l42y7QZtI8y6/adItDuv1OjHxF5HeXI15wNe7gmfFLcCNbxu45AngCu038T5mo/mFAQcL DTr/SpmtZPiOILKrFUksajYQkjbJT0oAAB4HCDo8zzeQQm2O8g X-QQ-XMRINFO: Nq+8W0+stu50tPAe92KXseR0ZZmBTk3gLg== X-QQ-RECHKSPAM: 0 Hi Conor, On Fri Mar 27, 2026 at 2:34 AM CST, Conor Dooley wrote: > On Thu, Mar 26, 2026 at 04:17:17PM +0800, Troy Mitchell wrote: >> From: Guodong Xu >>=20 >> Add k3 compatible string. > > That's obvious. What you need to explain is why it is not compatible with > the existing k1. > Thanks for the review. The SpacemiT K3 PDMA requires a new compatible string because it is not ful= ly backward compatible with the K1 implementation due to two main hardware dif= ferences: - Variable extended DRCMR base: The DRCMR (DMA Request/Command Register) ba= se address for extended DMA request numbers (>=3D 64) is different in the K3= hardware implementation. - Memory addressing capabilities: Unlike the K1 SoC, where some DMA masters= had memory addressing limitations (restricted to the 0-4GB space) and require= d a dedicated dma-bus, the K3 DMA masters have full memory addressing capabil= ities. I will update the commit message in the v3 series. -Troy