Re: [PATCH 2/4] spi: spi-fsl-dspi: Use non-coherent memory for DMA

From: Vladimir Oltean
Date: Thu Jun 12 2025 - 11:54:27 EST


On Thu, Jun 12, 2025 at 04:47:26PM +0100, James Clark wrote:
> > This is a fairly normal pattern, it's a big part of why the can_dma()
> > callback is per transfer - so you can do a copybreak and use PIO for
> > smaller transfers where the overhead of setting up DMA is often more
> > than the overhead of just doing PIO.
>
> Makes sense. Although for some reason two devices already use DMA for host
> mode and it's not that clear to me what the reason is.

I couldn't test them and I've kept them as they were.