Re: [RFC PATCH 0/2] dma: DMA slave device bringup tool

[Alexander Gordeev <a.gordeev.box@gmail.com>]

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!