From mboxrd@z Thu Jan 1 00:00:00 1970 From: geert@linux-m68k.org (Geert Uytterhoeven) Date: Thu, 9 Oct 2014 15:39:30 +0200 Subject: [PATCH v2 2/2] Documentation: dmaengine: Add a documentation for the dma controller API In-Reply-To: <20141007145226.GA17925@lukather> References: <1411746035-15882-1-git-send-email-maxime.ripard@free-electrons.com> <1411746035-15882-2-git-send-email-maxime.ripard@free-electrons.com> <7725507.nuHj4C7OxF@avalon> <5433D9AF.8020508@atmel.com> <20141007145226.GA17925@lukather> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Oct 7, 2014 at 4:52 PM, Maxime Ripard wrote: >> >> +These various types will also affect how the source and destination >> >> +addresses change over time, as DMA_SLAVE transfers will usually have >> >> +one of the addresses that will increment, while the other will not, >> >> +DMA_CYCLIC will have one address that will loop, while the other, will >> > >> > s/the other,/the other/ >> > >> >> +not change, etc. >> >> This is a little bit vague in my opinion. And usually, it is pretty >> implementation specific. > > Which is why we can't really be more precise. If you have any other > wording coming to your mind, I'm all for it :) Perhaps: Addresses pointing to RAM are typically incremented (or decremented) after each transfer. In case of a ring buffer, they may loop (DMA_CYCLIC). Addresses pointing to a device's register (e.g. a FIFO) are typically fixed. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds