Re: [PATCH RFC 2/2] dmaengine: fsl-edma: Support dynamic scatter/gather chaining

[Frank Li]

On Wed, May 06, 2026 at 04:01:37PM +0200, Benoît Monin wrote:
> On Tuesday, 5 May 2026 at 17:07:48 CEST, Frank Li wrote:
> > > >         how do you test it? and how much preformance improved?
> > > I did my tests by doing SPI transfers with the LPSPI controllers, doing DMA
> > > transactions with different number of buffers and different buffer sizes.
> > > Without chaining, interruptions on the SPI bus occur between each DMA
> > > transaction. With chaining, the activity on the SPI bus is continuous as
> > > long as DMA transactions are issued before the end of the current
> > > transaction.
> >
> > Does SPI support issue new transfers without wait for previous transfer
> > complete, or SPI transfer already support async queue?
> >
> This is done with a local version of fsl-lpspi driver adding a simple
> offload support by borrowing the DMA channels allocated to the SPI
> controller. I can then issue multiple DMA transactions with the dma_buf API
> of the IIO subsystem and trigger SG chaining.

Can you include these patches to reference?

Frank
>
> Best regards,
> --
> Benoît Monin, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com
>
>
>