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[95.222.30.189]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-4399c70e8e8sm1532704f8f.10.2026.02.26.11.43.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 26 Feb 2026 11:43:39 -0800 (PST) Date: Thu, 26 Feb 2026 20:43:36 +0100 From: Alexander Gordeev To: Vinod Koul 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 Thu, Feb 26, 2026 at 12:37:47PM +0530, Vinod Koul wrote: > > 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. Well, the idea is to trigger xfers using custom out-of-band tooling. > > 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 Yes, one could say so. It transfers off-CPU memory in one of FPGA implementations, which does not need any xfer setup. When attached to a camera however the xfer is triggered using a private tool that uses i2c - exactly as you guys noticed. The dmaengine driver for Avalon-MM Interface is not upstreamed yet. > ~Vinod Thanks!