On 1/19/19 2:25 AM, Christoph Hellwig wrote:
On Fri, Jan 18, 2019 at 10:37:46AM -0800, Liam Mark wrote:
Add support for configuring dma mapping attributes when mapping and unmapping memory through dma_buf_map_attachment and dma_buf_unmap_attachment.
Signed-off-by: Liam Mark lmark@codeaurora.org
And who is going to decide which ones to pass? And who documents which ones are safe?
I'd much rather have explicit, well documented dma-buf flags that might get translated to the DMA API flags, which are not error checked, not very well documented and way to easy to get wrong.
I'm not sure having flags in dma-buf really solves anything given drivers can use the attributes directly with dma_map anyway, which is what we're looking to do. The intention is for the driver creating the dma_buf attachment to have the knowledge of which flags to use.
Thanks, Laura