[PATCH 1/2] spi: sun4i: add DMA support

Michal Suchanek hramrach at gmail.com
Fri Feb 26 04:51:51 PST 2016


On 26 February 2016 at 13:25, Mark Brown <broonie at kernel.org> wrote:
> On Fri, Feb 26, 2016 at 07:56:56AM +0200, Priit Laes wrote:
>> From: Emilio López <emilio at elopez.com.ar>
>> This patch adds support for 64 byte or bigger transfers on the
>> sun4i SPI controller. Said transfers will be performed via DMA.
>> Signed-off-by: Emilio López <emilio at elopez.com.ar>
>> Tested-by: Michal Suchanek <hramrach at gmail.com>
>> Tested-by: Priit Laes <plaes at plaes.org>
>> ---
> You *must* sign off any patches you are sending, please see
> SubmittingPatches.

I have sent these patches in the past. Besides this non-technical
objection there were multiple technical objections.

IIRC one was that the driver does not handle the case when the DMA
channels are not available. As I understand it the channels are
exclusively reserved for a particular peripherial on sunxi platform so
this ShoulNotHappen(tm). So it's probably fine for the driver to fail
probe  when you have broken DT or no DMA engine support for sunxi

The driver could also work fully without DMA and there is a patch for
that also but since nobody will be testing that codepath it's probably
better to not include it.

I have not addressed the other objections so far.



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