From mboxrd@z Thu Jan 1 00:00:00 1970 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 BB867376489; Mon, 9 Mar 2026 11:24:37 +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=1773055477; cv=none; b=VFtkC+3oZ6cjh/sKDn0t84r6j9xjpkB4pjSDbyhTeqZ+PMzwcjvhWv61bp5ispZpnLiddmd1Kf6laG6YvF7QaE0QtSod0fHpUtEkgm+deO4GpuPQtmTUkkk2abeWWuHN8IhYaXplWvKz2shGl02e6PTQS8OIgDufONYRyeDfXAQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773055477; c=relaxed/simple; bh=YYv8pxQgJWca6hIYn2qoRloJNcRUEr26iVA0OhWlEEA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aGpO90StvNO3Ur9VoqzB4h4ERDRl+/Iy2Uak/F7H5w/mWUpI9sveI0gb74l77PGublNRX2jr31gITW3teVNn2hueG5QYYDJoFmzqsZwtSsFI9RgLBDhVnM/HpVa4dG4bP3Q3i+O6B95ZINucL0Nzww2L5wfgZlz+TKmCjN9GsGk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ek8j+14D; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ek8j+14D" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF1C7C4CEF7; Mon, 9 Mar 2026 11:24:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773055477; bh=YYv8pxQgJWca6hIYn2qoRloJNcRUEr26iVA0OhWlEEA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Ek8j+14DBss9fXPiAu8OxWzu0+bXUde8LQHxeNu1XsLSpI57NHxBrbBf6TuhcAPJG VGXkG3+Wznf6rvjZc10maDN1a6E/4jw2tNcyYE4Er2sdAR7t9o2AUzEk8u2cx6Ingz pqQWurAnto6paHxQwAx8MK7WMwWmWLxGZ8B2PqfvATJ5tTGFPa1pXwP2Z0IR/QFY0N 00xfsKPz1j7IMexA0AF0k/Uub0o28L1zebCSImOefV3D2Xn0mRLyYeCwBZSBmu/Ix9 0FI9Xh7PHai8UGfwCp6+Cir7g+O2gcnVJ8AcsZjXstY7Tzpcd3K9ny6DS7IfuWqlMe wWKaNLMbmzQmg== Date: Mon, 9 Mar 2026 12:24:33 +0100 From: Vinod Koul To: Frank Li Cc: Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 0/6] dmaengine: Add common dma_slave_config and split it into src and dst parts Message-ID: References: <20260114-dma_common_config-v1-0-64feb836ff04@nxp.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: <20260114-dma_common_config-v1-0-64feb836ff04@nxp.com> On 14-01-26, 12:12, Frank Li wrote: > Many DMA engine drivers store a dma_slave_config per channel. Propagate > this configuration into struct dma_chan to avoid duplicating the same > code in each driver. > > Much of dma_slave_config is identical for source and destination. Split > the configuration into src and dst groups and use a union to preserve > backward compatibility. This reduces the need for drivers to repeatedly > check the DMA transfer direction. The reason why we had both the src/dstn sides was intended method to allow upport ofr device to device dma. Some interest was shown for that at that time. I dont think we have such a user even now... -- ~Vinod