Messages in this thread | | | Date | Wed, 21 Sep 2011 12:15:42 +0530 | Subject | Re: [PATCHv3] DMAEngine: Define interleaved transfer request api | From | Jassi Brar <> |
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On 21 September 2011 12:02, Vinod Koul <vinod.koul@intel.com> wrote: > On Tue, 2011-09-20 at 23:38 +0530, Jassi Brar wrote: >> On 20 September 2011 22:22, Vinod Koul <vinod.koul@intel.com> wrote: >> > Also for slave transfers, how do we infer direction? >> I already explained to Barry. Here's it again. >> >> At any time, the dmac driver knows if the channel, on which the xfer is >> prepared/submitted is Slave or not. >> >> SLAVE Transfer >> dmaxfer_template.src_inc && !dmaxfer_template.dst_inc => DMA_TO_DEVICE >> !dmaxfer_template.src_inc && dmaxfer_template.dst_inc => DMA_FROM_DEVICE >> >> Mem->Mem Transfer >> dmaxfer_template.src_inc && !dmaxfer_template.dst_inc => Meaningless >> !dmaxfer_template.src_inc && dmaxfer_template.dst_inc => MemSet > Rather than each driver adding this logic with good chance of screwing > up, care to add this as helper in dmaengine.h > > Ideally, I would have preferred direction to be told explicitly, would > leave it you.. > I repeat yet again :- "This api is common to Slave as well as Mem<->Mem"
Even if we have slave clients specify DMA_TO/FROM_DEVICE, what flag do you suggest Mem->Mem clients use ? -- 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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