On 05/31/2016 08:15 PM, Konrad Rzeszutek Wilk wrote: > On Mon, May 30, 2016 at 01:54:06PM +0200, Krzysztof Kozlowski wrote: >> The dma-mapping core and the implementations do not change the >> DMA attributes passed by pointer. Thus the pointer can point to const >> data. However the attributes do not have to be a bitfield. Instead >> unsigned long will do fine: >> >> 1. This is just simpler. Both in terms of reading the code and setting >> attributes. Instead of initializing local attributes on the stack and >> passing pointer to it to dma_set_attr(), just set the bits. >> >> 2. It brings safeness and checking for const correctness because the >> attributes are passed by value. > > > .. why not go the next step a do an enum? Perhaps that should be mentioned > as part of the description? These are additive flags so to me this would look a little bit weird: enum dma_attr { DMA_ATTR_WRITE_BARRIER = 0x1, DMA_ATTR_WEAK_ORDERING = 0x2, DMA_ATTR_WRITE_COMBINE = 0x4, DMA_ATTR_NON_CONSISTENT = 0x8, ... } It doesn't really look like enumeration. Best regards, Krzysztof _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel