[EMAIL PROTECTED] wrote: > Bill Gatliff <[EMAIL PROTECTED]> wrote on 11/06/2008 10:36:58 AM: > >> Scott Wood wrote: >>> [EMAIL PROTECTED] wrote: >>>> In the Cafe driver, Linux Device Drivers 3rd Edition, and >>>> DMA-mapping.txt everyone talks about how to allocate buffers using >>>> dma/pci_alloc_coherent(), but no one talks about how to actually use >>>> it. I'm pretty sure (even in my ignorance) that just allocating a DMA >>>> coherent buffer and then copying in and out of it does NOT actually >>>> engage the underlying hardware and perform a DMA transfer. >> Does the "adma" stuff address this any? >> > > What is "adma"? > > Bruce > _______________________________________________ > Linuxppc-embedded mailing list > Linuxppc-embedded@ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-embedded >
Asynchronous DMA. See this paper, for example: http://www.power.org/devcon/07/Session_Downloads/PADC07_Aytac_Haluk_09_13_07_layout_FINAL.pdf It looks like the structure of interest is async_tx_submit. Beyond that, I can't offer much because I haven't used it. b.g. -- Bill Gatliff [EMAIL PROTECTED] _______________________________________________ Linuxppc-embedded mailing list Linuxppc-embedded@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-embedded