Hi, On 3/5/19 18:14, Robin Murphy wrote: > On 05/03/2019 15:53, Maxime Ripard wrote: >> Hi, >> >> On Fri, Mar 01, 2019 at 07:48:15PM +0200, Georgi Djakov wrote: >>> 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 <maxime.ripard@xxxxxxxxxxx> >>>> --- >>>> 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. >> >> I'm not sure I understand what you mean. You'd like two interconnect >> names, one called dma-memory, and one memory-dma? > > Hmm, yes, it's not like "dma" describes an actual source or destination > either :/ IIUC, it's a path (bus) that a dma device use to access some memory (read or/and write). So i have used source-destination above more in the sense of initiator-target or master-slave. My suggestion was just to change the reserved interconnect name from "dma" to "dma-mem" or "dma-memory". Thanks, Georgi
