On Mon, Oct 17, 2011 at 11:53 AM, Jassi Brar <jaswinder.si...@linaro.org> wrote: > > On 15 October 2011 23:05, Vinod Koul <vinod.k...@intel.com> wrote: > > > Another alternate approach could be to add one more argument to > > prep_slave_sg API which allows us to pass additional runtime specific > > parameters. This can be NULL and unused for existing drivers and used > in > > RIO and any future subsystems which want to use dmaengine. > > Thoughts...? > > > That doesn't sound much different than passing the data via > dma_chan.private during prep_slave_sg. Only now we add to > the number of arguments. One dma_chan may be used by multiple drivers requesting data transfer. In this case we will need a lock to keep dma_chan and its private coupled together. If we consider this coupling as a valid way we may think about adding a lock member into dma_chan structure. This will make locking more effective for configurations with multiple DMA channels.
> And then either this argument would be RapidIO specific (unfair > to other users) or generic. In latter case what would it look like ? It should not be RapidIO specific. Just transfer specific context that will be interpreted by participants. Given that we have a channel filtering mechanism there is a little chance of wrongful usage of that parameter. Alex. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
