On Thu, May 14, 2015 at 10:31:39PM +0200, Robert Jarzmik wrote: > Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> writes: > > > Hi Robert, > > > >> * DMA_CTRL_ACK > >> - - Undocumented feature > >> - - No one really has an idea of what it's about, besides being > >> - related to reusing the DMA transaction descriptors or having > >> - additional transactions added to it in the async-tx API > >> - - Useless in the case of the slave API > >> + - if set, the TX transfer can be reused after being completed. > > > > Your sentences should start with an upper-case letter. > Ack. > > >> + - there is a guarantee the TX won't be freed until it is acked > >> + by async_tx_ack() > > > > We never talked about what a "TX transfer" is in the > > documentation. That should be documented. > I'll remove the "TX", the transfer is widely used in this documentation. > > > > >> + - as a consequence, if a device driver wants to skip the dma_map_sg() and > >> + dma_unmap_sg() because the DMA'd data wasn't used, it can resubmit the > >> + transfer right after its completion. > > > > From a provider PoV, the data should always be mapped and / or > > allocated in coherent way, so I'm not sure how does that's relevant in > > the provider doc. > It's relevant because it says the mapping/unmapping is not necessary _between_ 2 > submission of a transfer. This implies it is mapped, as it is a requirement for > the very first submission. > > > Also, we should still mention that it's !slave API only. > Certainly not, it's fully slave API, that's the purpose of this patch. Its is not dependent on slave, it cna be used by slave as well as other users -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
