Re: [PATCH v4 2/2] Add Intel LGM soc DMA support.

From: Andy Shevchenko
Date: Mon Jul 13 2020 - 05:03:26 EST


On Mon, Jul 13, 2020 at 04:41:31PM +0800, Reddy, MallikarjunaX wrote:
> On 7/9/2020 7:09 PM, Andy Shevchenko wrote:
> > On Thu, Jul 09, 2020 at 02:01:06PM +0800, Amireddy Mallikarjuna reddy wrote:
> > > Add DMA controller driver for Lightning Mountain(LGM) family of SoCs.
> > >
> > > The main function of the DMA controller is the transfer of data from/to any
> > > DPlus compliant peripheral to/from the memory. A memory to memory copy
> > > capability can also be configured.
> > >
> > > This ldma driver is used for configure the device and channnels for data
> > > and control paths.
> > > +#include "../virt-dma.h"
> > I didn't find any evidence this driver utilizes virt-dma API in full.
> > For example, there is a virt_dma_desc structure and descriptor management around it.
> > Why don't you use it?
> Lgm dma soc has its own hardware descriptor.
> and each dma channel is associated with a peripheral, it is one to one
> mapping between channel and associated peripheral.

And this neither objects nor answers to my question.

Hint: above mentioned structure is an abstraction of hardware descriptors for
easier management in Linux kernel.

--
With Best Regards,
Andy Shevchenko