Messages in this thread | | | Date | Mon, 10 Oct 2011 15:23:46 +0530 | Subject | Re: [PATCHv4] DMAEngine: Define interleaved transfer request api | From | Jassi Brar <> |
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On 10 October 2011 14:48, Vinod Koul <vinod.koul@intel.com> wrote: > On Mon, 2011-10-10 at 14:46 +0530, Jassi Brar wrote: >> On 10 October 2011 12:23, Vinod Koul <vinod.koul@intel.com> wrote: >> > >> > +struct dmaxfer_memcpy_template { >> > + dma_addr_t src_start; >> > + dma_addr_t dst_start; >> > + bool src_inc; >> > + bool dst_inc; >> > + bool src_sgl; >> > + bool dst_sgl; >> > + size_t numf; >> > + size_t frame_size; >> > + struct data_chunk sgl[0]; >> > +}; >> > + >> > +struct dmaxfer_slave_template { >> > + dma_addr_t mem; >> > + bool mem_inc; >> > + size_t numf; >> > + size_t frame_size; >> > + struct data_chunk sgl[0]; >> > +}; >> > >> (1) Please tell how is dmaxfer_slave_template supposed to work on >> bi-directional channels? >> Keeping in mind, dma_slave_config.direction is marked to go away >> in future. > I didn't use dma_slave_config.direction. There is direction field in > corresponding prepare function. > ok but why not reduce 1 argument from api and embed that as the transfer's property in dmaxfer_slave_template, as I did ?
>> >> (2) >> * slave_template.mem <=> memcpy_template.src_start >> * slave_template.mem_inc <=> memcpy_template.src_inc >> >> So essentially >> memcpy_template := slave_template + src/dst_sgl + dst_start + dst_inc >> >> Even after this separation, there is nothing slave specific in >> dmaxfer_slave_template. The slave client still needs DMA_SLAVE_CONFIG >> to specify slave parameters of the transfer. >> You only save a few bytes in a _copy_ of memcpy_template. > Yes DMA_SLAVE_CONFIG is always required, this attempt was not aimed to > remove that, but I would be interested in it :) > Sorry then I don't see this "ambiguity"(if there really is any) removal worth adding an extra prepare when we already have 10 of them. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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