Hello Sylwester, On Fri, Mar 11, 2016 at 10:03 AM, Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx> wrote: > On 03/04/2016 09:20 PM, Javier Martinez Canillas wrote: >> The fimc_md_parse_port_node() function return 0 if an endpoint node is >> not found but according to Documentation/devicetree/bindings/graph.txt, >> a port must always have at least one enpoint. >> >> So return an -EINVAL errno code to the caller instead, so it knows that >> the port node parse failed due an invalid Device Tree description. > > I don't think it is forbidden to have a port node in device tree > containing no endpoint nodes. Empty port node means only that, > for example, a subsystem has a port/bus for connecting external > devices but nothing is actually connected to it. > That's not what I understood by reading both Documentation/devicetree/bindings/media/video-interfaces.txt and Documentation/devicetree/bindings/graph.txt but maybe these are not that clear about it or I just failed to parse the english. > In case of Exynos CSIS it might not be so useful to have an empty > port node specified in some top level *.dtsi file and only > the endpoints specified in a board specific dts file. Nevertheless, > I wouldn't be saying in general a port node must always have some > endpoint node defined. > Ok, but if that is valid then I believe that at the very least Documentation/devicetree/bindings/media/samsung-fimc.txt should explicitly mention which (sub)nodes are optional and which are required so the DT parsing logic could follow what's documented there. > I could apply this patch as it doesn't do any harm considering > existing dts files in the kernel tree (arch/arm/boot/dts/ > exynos4412-trats2.dts), but the commit description would need to > be changed. > I don't mind if you want to change the commit message but if those nodes are really optional then a follow-up should be to update the DT binding docs to make that clear IMHO. > -- > Thanks, > Sylwester > -- Best regards, Javier -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
