Re: [PATCH 4/7] spi: spi-geni-qcom: Add support for GPI dma

From: Vinod Koul
Date: Wed Jun 16 2021 - 08:02:43 EST


On 16-06-21, 12:35, Mark Brown wrote:
> On Wed, Jun 16, 2021 at 02:20:45PM +0530, Vinod Koul wrote:
>
> > Looking at the code, that is ideal case. Only issue I can see is that
> > core DMA mapping device being used is incorrect. The core would use
> > ctlr->dev.parent which is the spi0 device here.
>
> Why would the parent of the controller be a SPI device?

Sorry my bad, I meant the core use ctlr->dev.parent which in this case is
the SPI master device, 880000.spi

> > But in this case, that wont work. We have a parent qup device which is
> > the parent for both spi and dma device and needs to be used for
> > dma-mapping!
>
> > If we allow drivers to set dma mapping device and use that, then I can
> > reuse the core. Let me know if that is agreeable to you and I can hack
> > this up. Maybe add a new member in spi_controller which is filled by
> > drivers in can_dma() callback?
>
> Possibly, I'd need to see the code.

Ok, let me do a prototype and share ...

Thanks
--
~Vinod