On Sat, 1 Aug 2015 15:17:13 +0200 Robert Jarzmik <robert.jarz...@free.fr> wrote:
> Sometimes a scatter-gather has to be split into several chunks, or sub scatter > lists. This happens for example if a scatter list will be handled by multiple > DMA channels, each one filling a part of it. > > A concrete example comes with the media V4L2 API, where the scatter list is > allocated from userspace to hold an image, regardless of the knowledge of how > many DMAs will fill it : > - in a simple RGB565 case, one DMA will pump data from the camera ISP to > memory > - in the trickier YUV422 case, 3 DMAs will pump data from the camera ISP > pipes, > one for pipe Y, one for pipe U and one for pipe V > > For these cases, it is necessary to split the original scatter list into > multiple scatter lists, which is the purpose of this patch. > > ... > > include/linux/scatterlist.h | 5 ++ > lib/scatterlist.c | 189 > ++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 194 insertions(+) It's quite a bit of code for a fairly specialised thing. How ugly would it be to put this in a new .c file and have subsystems select it in Kconfig? -- 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
