From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Subject: Re: [PATCH v2 0/2] Add memcpy support for tegra210-adma Date: Tue, 6 Sep 2016 15:03:43 +0300 Message-ID: <5db4d7db-b1f4-c6af-de56-e8bb13ebc465@gmail.com> References: <319ca097-4b10-83b9-841c-52adccbb48ad@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <319ca097-4b10-83b9-841c-52adccbb48ad-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jon Hunter , Nicolin Chen , vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, gnurou-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org, ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org List-Id: linux-tegra@vger.kernel.org On 06.09.2016 14:33, Jon Hunter wrote: > > On 03/09/16 01:32, Nicolin Chen wrote: >> This series of patches add memcpy support for tegra210 ADMA engine. > > Thanks. Any reason you choose this DMA and not the APB DMA? The APB DMA > is more of a generic DMA and so for memcpy it would seem to be a good > choice and it is available on all Tegras not just Tegra210. > Just a small clarification: If I'm not mistaken, APB DMA is mem-to-device, while AHB DMA is mem-to-mem. So, you probably meant AHB and not the APB. > Furthermore, from a power standpoint the ADMA is in the audio power > domain and so using it for memcpy would mean the audio power domain is > turned on. It may not be a big deal for some, but given the APB is in > the CORE domain (always on when not in low-power) it seems like a better > choice for power as well. > -- Dmitry