Re: [PATCH v2 0/3] Add support for using external dma in SDHCI

[Rizvi, Mohammad Faiz Abbas]

+ Mark Brown

Chunyan,

On 11/21/2018 5:17 PM, Faiz Abbas wrote:
> Hi Chunyan,
>
> On 12/11/18 12:56 PM, Chunyan Zhang wrote:
> > Currently the generic SDHCI code in the Linux kernel supports the SD
> > standard DMA integrated into the host controller but does not have any
> > support for external DMA controllers implemented using dmaengine meaning
> > that custom code is needed for any systems that use a generic DMA
> > controller with SDHCI which in practice means any SDHCI controller that
> > doesn't have an integrated DMA controller so we should have this as a
> > generic feature.
> >
> > There are already a number of controller specific drivers that have dmaengine
> > code, and some could use sdhci.c actually, but needed to implement mmc_ops->request()
> > in their specific driver for sending command with external dma using dmaengine
> > framework, with this patchset, them will take advantage of the generic support.
> > TI's omap controller is the case as an example.
> >
> > Any comments are very appreciated.
>
> This is great. It helps us move am335x and am43xx platforms to
> sdhci-omap. What platforms have you tested this on?

Gentle ping on this. I tried testing these with an am335x-evm board. In 
their current condition, the card fails to enumerate altogether. The 
changes suggested by Adrian should fix this. Let me know when you post a v3.

Thanks,
Faiz