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 1737E38BF94; Thu, 26 Feb 2026 07:07:50 +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=1772089671; cv=none; b=YdNsLnTt7DhEsbYjEIo6ILBAfH1oCpUlhzPOas33Z8dxadojuX+0fVeBSldx/ISC0KMufLr/JL8NgJB0KLO8K/SAxM6tI4X4PCTyApUKTmUr3gPjw2WxdrYEJInmUMjsHLG0qPDv6vIB3Wfz2LE5ONRcZ+7QHFKdqftAFhTq7Qk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772089671; c=relaxed/simple; bh=RT93O7jTBol1YGqh80blX9bj2WHRyJuArkFn2VBcPEI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=p9/6rjuE/cXCXs5HRGR1Q6FaN3oBEQw/fLe6ssoqlkxZmIc3x/VdJSiRE35OH9al5Y+c0VXw4hLCs2AQX5yT5sQwKFSkn1DTDjWUJG1x0fJ3MlKISM6G3D33R18yCpNpD4zWzXaAO9lEARlSIbGK2LuVW6RgLvb2JCU8OwCspjg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=q04UTGbf; 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="q04UTGbf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48F10C19422; Thu, 26 Feb 2026 07:07:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772089670; bh=RT93O7jTBol1YGqh80blX9bj2WHRyJuArkFn2VBcPEI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=q04UTGbfGv4R3KRDHg3m8AYKAE5kCykWSpG9ZTuAxAHmas7jGfgOPqpct4D2U4mAd v2MEFMqJfX6SBuITztQmsZU4OTLEemutnAFlhDwUURnIUg3gS1kibO85xMDsP1E2cR PlIQowYBAw3YtGvdGuxzHSR5/YAbTyggXQU7TTbO1JEqpBcuRp3Bfw6UthqPZ2IOzl SSqqRwouAV/CBvHC6gl3ldbTFd4XjP4jBImNO8nYYxMtQHMd+Gnwimr44zo9kxc7KA ErDGzmuIYrH+M0Q/x8EYlbAUX5rpdLu7SvyoBFRM9qtIdNeHcmV+XzBf3CxT1z35S+ o9UfPx6r8y6iA== Date: Thu, 26 Feb 2026 12:37:47 +0530 From: Vinod Koul To: Alexander Gordeev Cc: Frank Li , dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 0/2] dma: DMA slave device bringup tool Message-ID: References: <20260221132248.17721-1-a.gordeev.box@gmail.com> Precedence: bulk X-Mailing-List: dmaengine@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: On 25-02-26, 22:10, Alexander Gordeev wrote: > On Wed, Feb 25, 2026 at 03:07:06PM +0530, Vinod Koul wrote: > > Hi Vinod, Frank, > > > > I am not sure if it can work for general dma engine because it slave setting > > > is tight coupling with FIFO settings and timing, some periphal require > > > start dma firstly, then enable DMA. some perphial require enable DMA first > > > then queue dma transfer. > > > > > > burst len is also related with FIFO 's watermark settings. > > > > Correct! > > > > I like the idea but it is not practical. Every dmaengine is tied to the > > peripheral for setting up the transfer. It is not a memcpy! How did you > > test it, which controller was used ..? > > I likely missing something, but how this differs from dmatest, which also > lacks any controller-specific setup? slave dma needs a peripheral to test. For example a spi/i2c etc dmaengine in slave mode will not work untill unless there is some signalling for dmaengine from peripheral to push/pull data. > I tested it on Avalon-MM Interface on Arria 10 FPGA and found it super- > useful - thus an attempt to share. Which driver is that? Seems more like a memcpy masked as slave to me -- ~Vinod