[PATCH RFC v4 2/5] dma: mpc512x: add support for peripheral transfers

Alexander Popov a13xp0p0v88 at gmail.com
Sat Dec 7 07:27:36 EST 2013


2013/10/6 Gerhard Sittig <gsi at denx.de>:
> On Thu, Oct 03, 2013 at 18:06 +0400, Alexander Popov wrote:
>> +
>> +             spin_lock_irqsave(&mchan->lock, flags);
>> +
>> +             if (cfg->direction == DMA_DEV_TO_MEM) {
>
> Note that cfg->direction is of a different type than
> DMA_DEV_TO_MEM (of different type than the 'direction' parameter
> in the preparation routine) -- it's mere coincidence that the
> numeric values happen to match at the moment.

Gerhard, it seems to me that this code is correct.
Cite from dmaengine.h:

  * struct dma_slave_config - dma slave channel runtime config
  * @direction: whether the data shall go in or out on this slave
  * channel, right now. DMA_TO_DEVICE and DMA_FROM_DEVICE are
  * legal values, DMA_BIDIRECTIONAL is not acceptable since we
  * need to differentiate source and target addresses.
  ...
  struct dma_slave_config {
          enum dma_transfer_direction direction;
          ...
  };

The comment above the definition is obsolete, isn't it?

Thanks
Alexander


More information about the Linuxppc-dev mailing list