On Thu, Jun 9, 2011 at 6:09 PM, Raju, Sundaram <sundaram@xxxxxx> wrote: > Generic buffer description: > A generic buffer can be split into number of frames which contain number of chunks inside them. The frames need not be contiguous, nor do the chunks inside a frame. > >    Â------------------------------------------------------------------- >    Â| Chunk 0 |ICG| Chunk 1 |ICG| ... |ICG| Chunk n |    Frame 0 >    Â------------------------------------------------------------------- >    Â|            Inter Frame Gap           | >    Â------------------------------------------------------------------- >    Â| Chunk 0 |ICG| Chunk 1 |ICG| ... |ICG| Chunk n |    Frame 1 >    Â------------------------------------------------------------------- >    Â|            Inter Frame Gap           | >    Â------------------------------------------------------------------- >    Â|                ........                  Â| >    Â------------------------------------------------------------------- >    Â|            Inter Frame Gap           | >    Â------------------------------------------------------------------- >    Â| Chunk 0 |ICG| Chunk 1 |ICG| ... |ICG| Chunk n |    Frame m >    Â------------------------------------------------------------------- IIUC the above figure, the work done by DMA controller remains the same, either by passing this as a transfer of the new type or as a normal sg-list - unless the DMAC driver attempts to reorder the transfers or the DMAC h/w natively supports some form of sg-list. For DMACs, that have no special support, different representation wouldn't make a difference. And if the DMAC does support the kind of fancy scatter-gather, it should be possible for the dma api driver to analyze the submitted 'normal' sg-list and program the transfers at one go. Besides, it should be possible to have a 'template' sequence of requests prepared already because usually, for above mentioned scenario, the parameters don't change across items in a list. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
