[PATCH v4 04/10] dma-engine: sun4i: Add support for Allwinner suniv F1C100s

Csókás Bence csokas.bence at prolan.hu
Sat Nov 2 02:06:49 PDT 2024


On 2024. 10. 31. 20:05, Amit Singh Tomar wrote:
>>    #define SUN4I_DMA_CFG_SRC_ADDR_MODE(mode)    ((mode) << 5)
>>    #define SUN4I_DMA_CFG_SRC_DRQ_TYPE(type)    (type)
>> +#define SUNIV_DMA_CFG_DST_DATA_WIDTH(width)    ((width) << 24)
>> +#define SUNIV_DMA_CFG_SRC_DATA_WIDTH(width)    ((width) << 8)
> 
> nit: Are the extra parentheses around width truly necessary? They seem 
> to be used throughout the file.

It's macro safety. So for instance if someone writes 
~SUNIV_DMA_CFG_DST_DATA_WIDTH(1 + 2), which would expand to ~1 + 2 << 24 
it doesn't get mis-interpreted as (~1) + (2 << 24) for instance. So 
yeah, I sure hope that _all code_ that has macros with parameters did 
not forget to wrap everything in parentheses, and not just "throughout 
[this] file".

Bence




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