Re: [PATCH 02/10] spi: dw-mid: always use duplex transfers when DMA

[Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>]

On Wed, 2014-09-24 at 09:44 +0100, Mark Brown wrote:
> On Thu, Sep 18, 2014 at 08:08:52PM +0300, Andy Shevchenko wrote:
> > In case of DMA we never got things done until we enable both channels. In case
> > of receive only or send only mode the user has to provide a dummy buffer.
> 
> The driver must never impose such requirements on clients, they
> shouldn't need to know about the quirks of the controller.  There's
> support in the core providing dummy buffers for transmit and receive,
> you should use that (possibly extending it so the dummies are only
> provided for DMA).


Currently driver in case of receiving or sending only will never call
the xfer_done from DMA callback since we never will have counter equal
to 2. So, the driver already relies on duplex mode. Am I missing
something?

-- 
Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>
Intel Finland Oy

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