Hello, On Thursday, June 16, 2011 9:57 AM Scott Jiang wrote: (snipped) > >> I used dma-contig allocator. I mean if offset is 0, I must get actual > >> addr from this offset. > > hi, Scott > > > > if it is single plane, surely the offset is 0 for plane 0 > yes, it is absolutely right. > > > what do you mean the actual addr ? > I should return virtual address of the buffer in get_unmapped_area callback. > > > > > > >> __find_plane_by_offset can do this. But it is an internal function. > >> I think there should be a function called vb2_get_unmapped_area to do > >> this in framework side. > > are you using soc_camera ? > > you can add your get_unmapped_area in soc_camera. > > if not, you can add it in your v4l2_file_operations ops, while still > > using videbuf2 to management your buffer. > yes, I have added this method, just copy __find_plane_by_offset code. > But it is ugly, it should have a vb2_get_unmapped_area like vb2_mmap. > These two operations are called by one system call, so they should > have a uniform looks. If videobuf2-core and its memory allocator interface lacks some operations that are essential for no-mmu systems, please just add them. Frankly I have no experience with Linux no-mmu systems, so I might have missed something that is required for no-mmu case. Best regards -- Marek Szyprowski Samsung Poland R&D Center -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
