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=1793796987; b=TMKU3AqTteXRgz2vyLElr9agncCvNdMsijYlRLq+gXD4cTngYSqItf/Z/nnVbrdFgT7j P30N024c4az4xY4I3nFa/p4VL8sgAK91pfQ8Ke2CIyYvoH6nYhNllwkLEIySbIFLK3vhv OrUBnsVhDiBxutcKihWPArAO6fvp4JGGR8+nQTzQynm/D84O9ZYqbtA8N4kjEIoKgdx2D 1j1tOGe68w+ZlETfbbUxwf9CjHeeIQSsohE5jHNU73a5r4hwn1Ij8GaJADtxLmLTivpQX cFvSdw4t43CfteU6JVyyc5PabkDQ5RUpCZnciu/6eog7lTX9b/r7YTDh3Yv+Sd8nfJg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793796987; 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=WPFVDhDki1CZ9MBThbVi68MgMjOiFRfNBMjVL4sxVnA=; b=hbHa4Jff5o+vtO7ZM+GExWC2H2Yz3q6WO7pSM3zVL8B37P95NANh1sQ0YOXMkyeYWwn+ fVqERDKcHkj780YelAFSSc2tSIOaFnLjULTfcdPplRkzCzlyrTqyXqyf/P/urYXWEmmO8 McEG/CpgTeuR3ML0hjYVpttQAwJ7leb86oCoNAAs24GLBR/YfB7+uOcJCGgJjVbqtWrsx e74q7vKl8c4UxXt0SdL2WhmVvMbhErLCbF498lqqgg3jBOAMU4t63282fgPk7gmBP3//I Sk/hAhE2h9QKfaWnA4up7I3Dg/ukT70OpfELYzVMEkoHcJLHZxIbgYWt72DWUW2QoHQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none header.from=sang-engineering.com; spf=pass smtp.mailfrom=sang-engineering.com; 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 81E2C606A326 for ; Wed, 4 Nov 2026 12:56:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 81E2C606A326 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 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=WPFV DhDki1CZ9MBThbVi68MgMjOiFRfNBMjVL4sxVnA=; b=J987gDQpgu3JJYvLTekS IAQaQvz050/iGPqFKLlZjAYHb+zSppMq41f1Q69KZeNdMPsFObXAdz2oUOQAkgQD WugXA+/hlC0IgAr7zo8pcUYoOIPJ9UVXZ80x08FPFFifl/bIOYq196iIXRwdN5wG 55UE5TjaNa8fNACJ+iXxTm1ROOQAqt1VKd8Bi9iyY9Zr4dzDUq33MwEA0P25ta9w KMsPzsKaJE4x99YK7a5GJMypYgt75p+FmvGGKYroSj4Gnta9zvdWpE8YqhTGCpSV n67kBqF+5JJmE2uamSHtw4u5QTqjH5JRkzN/22PvlcLAePKB+jtoBrr2waghyqCb SA== Received: (qmail 728268 invoked from network); 4 Nov 2026 13:56:16 +0100 Received: by mail.zeus03.de with ESMTPSA (TLS_AES_256_GCM_SHA384 encrypted, authenticated); 4 Nov 2026 13:56:16 +0100 X-UD-Smtp-Session: l3s3148p1@Ko+B53JfONLAwtcC Date: Wed, 4 Nov 2026 14:56:14 +0200 From: Wolfram Sang To: Frank.Li@oss.nxp.com Cc: Andi Shyti , Geert Uytterhoeven , Magnus Damm , Sumit Semwal , Christian =?utf-8?B?S8O2bmln?= , Philipp Stanner , "open list:RENESAS R-CAR I2C DRIVERS" , "open list:I2C SUBSYSTEM HOST DRIVERS" , open list , "open list:DMA BUFFER SHARING FRAMEWORK:Keyword:bdma_(?:buf|fence|resv)b" , "open list:DMA BUFFER SHARING FRAMEWORK:Keyword:bdma_(?:buf|fence|resv)b" , "moderated list:DMA BUFFER SHARING FRAMEWORK:Keyword:bdma_(?:buf|fence|resv)b" , imx@lists.linux.dev, vkoul@kernel.org, Frank Li Subject: Re: [PATCH 1/1] i2c: use dmaengine_get_dma_device() instead of chan->device->dev Message-ID: References: <20261103212655.1774644-1-Frank.Li@oss.nxp.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: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="aloAu6dyzoHKdfGs" Content-Disposition: inline In-Reply-To: <20261103212655.1774644-1-Frank.Li@oss.nxp.com> --aloAu6dyzoHKdfGs Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Frank, On Tue, Nov 03, 2026 at 04:26:54PM -0500, Frank.Li@oss.nxp.com wrote: > From: Frank Li >=20 > Replace direct dma_chan::device::dev access with the proper > dmaengine_get_dma_device() for consumer API. >=20 > chan->device->dev is not always the device used for DMA mapping. Some DMA > engines support per-channel IOMMU mappings, so different channels may use > different DMA devices. dmaengine_get_dma_device() returns the correct > device for each channel. >=20 > This also prepares for making the DMA engine provider data structures > private. DMA consumers should not access DMA engine internals directly. Thanks for this, looks useful. > - dma_addr =3D dma_map_single(chan->device->dev, buf, len, dir); > - if (dma_mapping_error(chan->device->dev, dma_addr)) { > + dma_addr =3D dma_map_single(dmaengine_get_dma_device(chan), buf, len, d= ir); > + if (dma_mapping_error(dmaengine_get_dma_device(chan), dma_addr)) { > dev_dbg(dev, "dma map failed, using PIO\n"); I think we should populate a dma_dev-variable here and reuse it instead of calling dmaengine_get_dma_device() twice. Happy hacking, Wolfram --aloAu6dyzoHKdfGs Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAmrrK2kACgkQFA3kzBSg KbbJkw/+KALNP+8RejO8KJPzQd6OWD7TMRhgH2+HxmyTJ1AVqOnGYuXP3m53IiNo C53q1AgBUCbn3daNJxDIjy1zDR1CnXZWtOX8qMtD+2RSI1/LOj1L3R2bkbtsECeW 4yichs5kH6x9H9acHy08a5ogo4WDnO34sAHpkvUFp1XFTCRbA5DNGlacr/IgwI/0 j8ZM9QpzVpivV6dXun0x+uO9vjAF6QUboYWWfmuRi7B26QGe1ySimvNZMg4hXLkU dt8mwJw5D4D/PJtrvIqhrggeA1HZ95Dbs3I7WqW/gWtEV2wmX09SBP+C8IDmgGBv Hur62uN8+FkPiEOySHVP0Hz8gYN8rZiJw6C9fyymbLRaGpSnuHF132zNCWmlixLs U8IfNCO7YQ+Lpu5sFy2cMQEqG39WtL0kVbEYy2o4KTtWmJoDIzBh83xHpIm/ty2v oAEcfLLJaK/DaAGN+B4fUUwYLBJfuz1dvIaF1FCNsnJhdxi7rCJZ4Fl9s3s4ccjy AeiAw9Ou+7ViHnrLV1YBIak+REikYlOxK6L0enCXgojJbER6j5TTx6zdMIYiF3GN Cvbisbho469h59MaRPwQWS4jRIGp3/02j9NrH61WfVRQfHIB8LgVj9tMhJUzuKa7 8UOeDsLDX5osLe5IsCnKoGO1ZNg4KZ5I6tjfgX1FSpu5wmrbgIs= =Kk23 -----END PGP SIGNATURE----- --aloAu6dyzoHKdfGs--