From mboxrd@z Thu Jan 1 00:00:00 1970 From: Georgi Djakov Subject: Re: [PATCH v3 1/7] dt-bindings: interconnect: Add a dma interconnect name Date: Fri, 1 Mar 2019 19:48:15 +0200 Message-ID: <553c987c-da9a-1f85-fb16-4b9fe17dd14b@linaro.org> References: <43eeca13733faefe62f9facc25b8e88f7e593f61.1549897336.git-series.maxime.ripard@bootlin.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <43eeca13733faefe62f9facc25b8e88f7e593f61.1549897336.git-series.maxime.ripard@bootlin.com> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Maxime Ripard , Mark Rutland , Rob Herring , Frank Rowand , Chen-Yu Tsai Cc: devicetree@vger.kernel.org, Thomas Petazzoni , Arnd Bergmann , dri-devel@lists.freedesktop.org, Paul Kocialkowski , Yong Deng , Robin Murphy , Dave Martin , linux-arm-kernel@lists.infradead.org List-Id: dri-devel@lists.freedesktop.org Hi Maxime, On 2/11/19 17:02, Maxime Ripard wrote: > The current DT bindings assume that the DMA will be performed by the > devices through their parent DT node, and rely on that assumption for the > address translation using dma-ranges. > > However, some SoCs have devices that will perform DMA through another bus, > with separate address translation rules. We therefore need to express that > relationship, through the special interconnect name "dma". > > Signed-off-by: Maxime Ripard > --- > Documentation/devicetree/bindings/interconnect/interconnect.txt | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/Documentation/devicetree/bindings/interconnect/interconnect.txt b/Documentation/devicetree/bindings/interconnect/interconnect.txt > index 5a3c575b387a..e69fc2d992c3 100644 > --- a/Documentation/devicetree/bindings/interconnect/interconnect.txt > +++ b/Documentation/devicetree/bindings/interconnect/interconnect.txt > @@ -51,6 +51,9 @@ interconnect-names : List of interconnect path name strings sorted in the same > interconnect-names to match interconnect paths with interconnect > specifier pairs. > > + Reserved interconnect names: > + * dma: Path from the device to the main memory of the system Bikeshed: As it's from the device to the main memory, maybe here we can also denote this my calling the path dma-mem or dma-memory. For other paths, we are trying to mention both the source and the destination and maybe it would be good to be consistent although this is special one. Thanks, Georgi