Re: SPI for IMX6x with cyclic DMA

Andrea Tessadri <tessadriandrea@...>

Great, thanks! 

Il gio 13 ago 2020, 17:17 Eric Nelson <ericnelsonaz@...> ha scritto:
Hi Andrea,

On 8/13/20 7:28 AM, Andrey Zhizhikin wrote:
> On Thu, Aug 13, 2020 at 3:31 PM Andrea Tessadri
> <tessadriandrea@...> wrote:
>> I've just developed and tested cyclic DMA transfer for a SPI device on a IMX6UL with kernel 4.9.88


>> I wanted to have a single SPI transfer repeated continuously in order to feed a DAC for generation of a particular waveform for a medical device, without interruption and minimal jitter (this is why I though to make the change at low level, instead of making the protocol driver to pump several identical messages to SPI subsystem)
>> I am wondering if this feature could be interesting for other applications and if it is worth to submit a patch for drivers/spi/spi-imx.c
> This is definitely a wrong list for those changes, it should go to
> LKML instead. This list is used for discussions regarding Yocto
> Project distribution, and I believe you're interested in merging your
> changes into Kernel. For that you should post this RFC to LKML.

Andrey is right that kernel patches aren't submitted through this list.

Depending on how you've implemented this, the proper mailing list will
be either or both linux-spi and dmaengine as noted here:

That said, there are probably more potential users on this list,
and posting it here might get more feedback than those lists.

And to answer your question about whether it is worth submitting the
patch set, I'd say "yes". Even if it's not accepted, it might prove
useful to others.



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