On 07-Aug-23 21:19, Andrew Davis wrote: > On 8/7/23 7:56 AM, Aradhya Bhatia wrote: >> Hi Jayesh, >> >> On 07-Aug-23 17:54, Jayesh Choudhary wrote: >>> Hello Aradhya, >>> >>> Thank you for the review. >>> >>> On 05/08/23 00:52, Aradhya Bhatia wrote: >>>> Hi Jayesh, >>>> >>>> >>>> On 03-Aug-23 13:34, Jayesh Choudhary wrote: >>>>> From: Rahul T R <r-ravikumar@xxxxxx> >>>>> >>>>> Enable display for J784S4 EVM. >>>>> >>>>> Add assigned clocks for DSS, DT node for DisplayPort PHY and pinmux >>>>> for >>>>> DP HPD. Add the clock frequency for serdes_refclk. >>>>> >>>>> Add the endpoint nodes to describe connection from: >>>>> DSS => MHDP => DisplayPort connector. >>>>> >>>>> Also add the GPIO expander-4 node and pinmux for main_i2c4 which is >>>>> required for controlling DP power. Set status for all required nodes >>>>> for DP-0 as "okay". >>>>> >>>>> Signed-off-by: Rahul T R <r-ravikumar@xxxxxx> >>>>> [j-choudhary@xxxxxx: move all the changes together to enable DP-0 in >>>>> EVM] >>>>> Signed-off-by: Jayesh Choudhary <j-choudhary@xxxxxx> >>>>> --- >>>>> arch/arm64/boot/dts/ti/k3-j784s4-evm.dts | 119 >>>>> +++++++++++++++++++++++ >>>>> 1 file changed, 119 insertions(+) >>> >>> [...] >>> >>>>> + reg = <0>; >>>>> + cdns,num-lanes = <4>; >>>>> + #phy-cells = <0>; >>>>> + cdns,phy-type = <PHY_TYPE_DP>; >>>>> + resets = <&serdes_wiz4 1>, <&serdes_wiz4 2>, >>>>> + <&serdes_wiz4 3>, <&serdes_wiz4 4>; >>>>> + }; >>>>> +}; >>>>> + >>>>> +&mhdp { >>>>> + status = "okay"; >>>>> + pinctrl-names = "default"; >>>>> + pinctrl-0 = <&dp0_pins_default>; >>>>> + phys = <&serdes4_dp_link>; >>>>> + phy-names = "dpphy"; >>>>> +}; >>>>> + >>>>> +&dss_ports { >>>>> + port { >>>> >>>> Port index has not been added here. Since this port outputs to MHDP >>>> bridge, this should be "port@0", and a "reg = <0>;" property should be >>>> added below (along with the address and size cells properties). >>>> >>>> I suppose this works functionally in this case, because the port gets >>>> defaulted to "0" by the driver. But in future, when we add support for >>>> other dss output(s) on j784s4-evm, the driver will need indices to >>>> distinguish among them. >>>> >>> >>> Okay. It makes sense. >>> Just one thing here. Adding reg here would require it to have #address- >>> cells and #size-cell but since we have only single child port that too >>> at reg=<0>, it would throw dtbs_check warning: >>> >>> arch/arm64/boot/dts/ti/k3-j784s4-main.dtsi:1828.20-1831.5: Warning >>> (graph_child_address): /bus@100000/dss@4a00000/ports: graph node has >>> single child node 'port@0', #address-cells/#size-cells are not necessary >>> also defined at arch/arm64/boot/dts/ti/k3-j784s4-evm.dts:911.12-919.3 >>> >> >> Okay! Was not aware about this. I still think "port@0" should be >> specified instead of just "port" and the warning should be ignored, if >> possible. >> > > Do not ignore new DT check warnings, if you go with "port@0" (which you > need to do as the "ti,j721e-dss" binding requires it) you must also add > the #address-cells/#size-cells. > The warning that Jayesh mentioned above comes when "port@0" is mentioned, *along-with* the #address-cells/#size-cells properties. Essentially, it wants us to not use "port@0" when only single port is being added whose reg values is 0. This warning does not come when only a single port other than 0, "port@1" for e.g., is being used. That's the warning, that should get ignored, if possible. However, just mentioning "port@0", without the #address-cells/ #size-cells, would be plain wrong. Regards Aradhya > >> If there were only a "port@1" child node, this warning would not have >> come up, and I believe "port@0" should be treated just the same. >> >> Moreover, while we can add these properties at a later stage as an >> incremental patch, adding the size and address cells in the dtsi would >> affect other platform dts files as well, that use this SoC. >> >> For e.g., the patch 5/5 of this series, on AM69-SK will still require >> the size and address cells for its ports. The clean up then will be that >> much more, when adding those incremental patches. >> >> Anyway, I will let Nishanth and Vignesh take the final call on this. >> >> Regards >> Aradhya >> >>> >>>>> + dpi0_out: endpoint { >>>>> + remote-endpoint = <&dp0_in>; >>> >>> >>> [...] >>