Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> writes: > On 25/01/2024 10:10, esben@xxxxxxxxxx wrote: >> Conor Dooley <conor@xxxxxxxxxx> writes: >> >>> On Wed, Jan 24, 2024 at 03:33:06PM +0100, Esben Haabendal wrote: >>>> Time Based Scheduling can be enabled per TX queue, if supported by the >>>> controller. >>> >>> If time based scheduling is not supported by the controller, then the >>> property should not be present! The presence of a property like this >>> should mean that the feature is supported, using it is up to the >>> operating system. >>> >>> That said, why is this a property that should be in DT? >> >> It is added to the tx-queues-config object of snps,dwmac bindings. This >> entire object is about configuration of the ethernet controller, which >> is also what the purpose of the snps,time-based-scheduling. >> So yes, it is not specifically about describing what the hardware is >> capable of, but how the hardware is configured. It is a continuation of >> the current driver design. >> >>> If support is per controller is it not sufficient to use the >>> compatible to determine if this is supported? >> >> Are you suggesting to include the mapping from all supported compatible >> controllers to which TX queues supports TBS in the driver code? What >> would the benefit of that compared to describing it explicitly in the >> binding? > > The benefit is complying with DT bindings rules, saying that bindings > describe hardware pieces, not drivers. Understood. >> And for the purpose of the above question, I am talking about it as if >> the binding was describing the hardware capability and not the >> configuration. > > "if"? You wrote it is for driver design... If you look at the current driver, all the devicetree bindings under rx-queues-config and tx-queues-config are violating the DT binding rules. Cleaning up that requires quite some work and I guess will break backwards compatibility to some extend. But that is another story. I will respin the patch according to Conor's suggestion. /Esben
