[PATCH v5 0/2] i2c: add DMA support for freescale i2c driver

Yao Yuan yao.yuan at freescale.com
Wed Jul 23 20:36:34 PDT 2014


Hi,

Marek Vasut wrote:
> On Wednesday, July 23, 2014 at 10:24:41 AM, Yuan Yao wrote:
> > Changed in v5:
> > - add "*chan_dev = dma->chan_using->device->dev" for reduce the call time.
> 
> Did you check if the compiler generates different code ?
> 

Sorry, I didn't compare the assembly code. It's a subtle change. 
As you mentioned the "noodle" before.

Old:
dma_map_single(dma->chan_using->device->dev, ...);
dma_mapping_error(dma->chan_using->device->dev, ...);
dma_unmap_single(dma->chan_using->device->dev, ...);
	
New:
struct device *chan_dev = dma->chan_using->device->dev;
dma_map_single(chan_dev, ...);
dma_mapping_error(chan_dev, ...);
dma_unmap_single(chan_dev, ...);

> > - add the test logs.
> 
> [...]
> 
> Best regards,
> Marek Vasut



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