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There is no importer and exporter >>> here. >> >> Yeah, and exactly that's what I'm pointing out as problem here. >> >> You are using the inter driver framework for something internal to >> the driver. That is an absolutely clear NAK! >> >> We could discuss that, but you guys are just sending around patches >> to do this without any consensus that this is a good idea. > > s/you guys/you/ if you have to blame anyone - I'm the only s-o-b in > these patches. I'm sending these to _build consensus_ on what may be a > good > use for it showing a real problem it's helping to fix. Well a cover letter would have been helpful, my impression was that you have a larger set and just want to upstream some minor DMA-buf changes necessary for it. Now I know why people are bugging me all the time to add cover letters to add more context to my sets. > > From its documentation: > >  * The type :c:type:`struct dma_buf_map ` and its helpers > are >  * actually independent from the dma-buf infrastructure. When sharing > buffers >  * among devices, drivers have to know the location of the memory to > access >  * the buffers in a safe way. :c:type:`struct dma_buf_map ` >  * solves this problem for dma-buf and its users. If other drivers or >  * sub-systems require similar functionality, the type could be > generalized >  * and moved to a more prominent header file. > > if there is no consensus and a better alternative, I'm perfectly fine in > throwing it out and using the better approach. When Thomas Zimmermann upstreamed the dma_buf_map work we had a discussion if that shouldn't be independent of the DMA-buf framework. The consensus was that as soon as we have more widely use for it this should be made independent. So basically that is what's happening now. I suggest the following approach: 1. Find a funky name for this, something like iomem_, kiomap_ or similar. 2. Separate this from all you driver dependent work and move the dma_buf_map structure out of DMA-buf into this new whatever_ prefix. 3. Ping Thomas, LKML, me and probably a couple of other core people if this is the right idea or not. 4. Work on dropping the map parameter from dma_buf_vunmap(). This is basically why we can't modify the pointers returned from dma_buf_vmap() and has already cause a few problems with dma_buf_map_incr(). Regards, Christian. > > Lucas De Marchi