Hi Rebecca, On Monday 04 June 2012 12:34:23 Rebecca Schultz Zavin wrote: > I have a system where the data is planar, but the kernel drivers > expect to get one allocation with offsets for the planes. I can't > figure out how to do that with the current dma_buf implementation. I > thought I could pass the same dma_buf several times and use the > data_offset field of the v4l2_plane struct but it looks like that's > only for output. Am I missing something? Is this supported?
data_offset is indeed for video output only at the moment, and doesn't seem to be used by any driver in mainline for now. I can't really see a reason why data_offset couldn't be used for video capture devices as well. Sanity checks are currently missing. For output devices we should check that data_offset + bytesused < length in the vb2 core. For input devices the check will have to be performed by drivers. Taking data_offset into account automatically would also be useful. I think most of that should be possible to implement in the allocators. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
