On Tue, Jun 18, 2013 at 06:04:44PM +0900, Inki Dae wrote: > > > > -----Original Message----- > > From: Russell King - ARM Linux [mailto:linux@xxxxxxxxxxxxxxxx] > > Sent: Tuesday, June 18, 2013 5:43 PM > > To: Inki Dae > > Cc: 'Maarten Lankhorst'; 'linux-fbdev'; 'Kyungmin Park'; 'DRI mailing > > list'; 'Rob Clark'; 'myungjoo.ham'; 'YoungJun Cho'; 'Daniel Vetter'; > > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-media@xxxxxxxxxxxxxxx > > Subject: Re: [RFC PATCH v2] dmabuf-sync: Introduce buffer synchronization > > framework > > > > On Tue, Jun 18, 2013 at 02:27:40PM +0900, Inki Dae wrote: > > > So I'd like to ask for other DRM maintainers. How do you think about it? > > it > > > seems like that Intel DRM (maintained by Daniel), OMAP DRM (maintained > > by > > > Rob) and GEM CMA helper also have same issue Russell pointed out. I > > think > > > not only the above approach but also the performance is very important. > > > > CMA uses coherent memory to back their buffers, though that might not be > > true of memory obtained from other drivers via dma_buf. Plus, there is > > no support in the CMA helper for exporting or importng these buffers. > > > > It's not so. Please see Dave's drm next. recently dmabuf support for the CMA > helper has been merged to there. The point stands: CMA is DMA coherent memory. It doesn't need and must never be dma-map-sg'd or dma-sync'd or dma-unmap'd. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
