linux-kernel - Re: [PATCH 1/3] dmaengine: ae4dma: Initial ae4dma controller driver with multi channel

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Message-ID: <ZSzb9OEo6cIbln3A@matsya>
Date:   Mon, 16 Oct 2023 12:15:08 +0530
From:   Vinod Koul <vkoul@...nel.org>
To:     "Mehta, Sanju" <Sanju.Mehta@....com>
Cc:     "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
        "dan.j.williams@...el.com" <dan.j.williams@...el.com>,
        "robh@...nel.org" <robh@...nel.org>,
        "mchehab+samsung@...nel.org" <mchehab+samsung@...nel.org>,
        "davem@...emloft.net" <davem@...emloft.net>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "dmaengine@...r.kernel.org" <dmaengine@...r.kernel.org>
Subject: Re: [PATCH 1/3] dmaengine: ae4dma: Initial ae4dma controller driver
 with multi channel

On 14-10-23, 08:26, Mehta, Sanju wrote:
> [AMD Official Use Only - General]

??

> > > diff --git a/drivers/dma/ae4dma/ae4dma-pci.c
> > > b/drivers/dma/ae4dma/ae4dma-pci.c new file mode 100644 index
> > > 0000000..a77fbb5
> > > --- /dev/null
> > > +++ b/drivers/dma/ae4dma/ae4dma-pci.c
> > > @@ -0,0 +1,247 @@
> > > +// SPDX-License-Identifier: GPL-2.0-only
> > > +/*
> > > + * AMD AE4DMA device driver
> > > + * -- Based on the PTDMA driver
> >
> > cant we use ptdma driver to support both cores?
> >
> AE4DMA has multiple channels per engine, whereas PTDMA is limited to a single channel per engine. Furthermore, there are significant disparities in both the DMA engines and their respective handling methods. Hence wanted to keep separate codes for PTDMA and AE4DMA.

Pls wrap your replies to 80chars!

The channel count should be configurable and for the handling methods,
you can have low level handler functions for each controller which can
be selected based on device probe

I feel reuse of code is better idea than having two different drivers
-- 
~Vinod