Re: [PATCH v2 00/11] Add Milk-V Pioneer RISC-V board support

From: Chen Wang
Date: Fri Sep 22 2023 - 06:24:43 EST

Regards,

unicornx

Conor Dooley <conor.dooley@xxxxxxxxxxxxx> 于2023年9月20日周三 18:01写道：
>
> On Wed, Sep 20, 2023 at 02:33:48PM +0800, Chen Wang wrote:
> > Milk-V Pioneer [1] is a developer motherboard based on SOPHON SG2042 [2]
> > in a standard mATX form factor. Add minimal device
> > tree files for the SG2042 SOC and the Milk-V Pioneer board.
>
> Please run dtbs_check with W=1 set & fix the below issues:
>
> sg2042-cpus.dtsi:1600.25-1607.5: Warning (unit_address_vs_reg): /cpus/l2-cache@0: node has a unit name, but no reg or ranges property
> sg2042-cpus.dtsi:1609.25-1616.5: Warning (unit_address_vs_reg): /cpus/l2-cache@1: node has a unit name, but no reg or ranges property
> sg2042-cpus.dtsi:1618.25-1625.5: Warning (unit_address_vs_reg): /cpus/l2-cache@2: node has a unit name, but no reg or ranges property
> sg2042-cpus.dtsi:1627.25-1634.5: Warning (unit_address_vs_reg): /cpus/l2-cache@3: node has a unit name, but no reg or ranges property
> sg2042-cpus.dtsi:1636.25-1643.5: Warning (unit_address_vs_reg): /cpus/l2-cache@4: node has a unit name, but no reg or ranges property
> sg2042-cpus.dtsi:1645.25-1652.5: Warning (unit_address_vs_reg): /cpus/l2-cache@5: node has a unit name, but no reg or ranges property
> sg2042-cpus.dtsi:1654.25-1661.5: Warning (unit_address_vs_reg): /cpus/l2-cache@6: node has a unit name, but no reg or ranges property
> sg2042-cpus.dtsi:1663.25-1670.5: Warning (unit_address_vs_reg): /cpus/l2-cache@7: node has a unit name, but no reg or ranges property
> sg2042-cpus.dtsi:1672.25-1679.5: Warning (unit_address_vs_reg): /cpus/l2-cache@8: node has a unit name, but no reg or ranges property
> sg2042-cpus.dtsi:1681.25-1688.5: Warning (unit_address_vs_reg): /cpus/l2-cache@9: node has a unit name, but no reg or ranges property
> sg2042-cpus.dtsi:1690.27-1697.5: Warning (unit_address_vs_reg): /cpus/l2-cache@10: node has a unit name, but no reg or ranges property
> sg2042-cpus.dtsi:1699.27-1706.5: Warning (unit_address_vs_reg): /cpus/l2-cache@11: node has a unit name, but no reg or ranges property
> sg2042-cpus.dtsi:1708.27-1715.5: Warning (unit_address_vs_reg): /cpus/l2-cache@12: node has a unit name, but no reg or ranges property
> sg2042-cpus.dtsi:1717.27-1724.5: Warning (unit_address_vs_reg): /cpus/l2-cache@13: node has a unit name, but no reg or ranges property
> sg2042-cpus.dtsi:1726.27-1733.5: Warning (unit_address_vs_reg): /cpus/l2-cache@14: node has a unit name, but no reg or ranges property
> sg2042-cpus.dtsi:1735.27-1742.5: Warning (unit_address_vs_reg): /cpus/l2-cache@15: node has a unit name, but no reg or ranges property
> sg2042-cpus.dtsi:256.15-275.5: Warning (unique_unit_address_if_enabled): /cpus/cpu@0: duplicate unit-address (also used in node /cpus/l2-cache@0)
> sg2042-cpus.dtsi:277.15-296.5: Warning (unique_unit_address_if_enabled): /cpus/cpu@1: duplicate unit-address (also used in node /cpus/l2-cache@1)
> sg2042-cpus.dtsi:298.15-317.5: Warning (unique_unit_address_if_enabled): /cpus/cpu@2: duplicate unit-address (also used in node /cpus/l2-cache@2)
> sg2042-cpus.dtsi:319.15-338.5: Warning (unique_unit_address_if_enabled): /cpus/cpu@3: duplicate unit-address (also used in node /cpus/l2-cache@3)
> sg2042-cpus.dtsi:340.15-359.5: Warning (unique_unit_address_if_enabled): /cpus/cpu@4: duplicate unit-address (also used in node /cpus/l2-cache@4)
> sg2042-cpus.dtsi:361.15-380.5: Warning (unique_unit_address_if_enabled): /cpus/cpu@5: duplicate unit-address (also used in node /cpus/l2-cache@5)
> sg2042-cpus.dtsi:382.15-401.5: Warning (unique_unit_address_if_enabled): /cpus/cpu@6: duplicate unit-address (also used in node /cpus/l2-cache@6)
> sg2042-cpus.dtsi:403.15-422.5: Warning (unique_unit_address_if_enabled): /cpus/cpu@7: duplicate unit-address (also used in node /cpus/l2-cache@7)
> sg2042-cpus.dtsi:424.15-443.5: Warning (unique_unit_address_if_enabled): /cpus/cpu@8: duplicate unit-address (also used in node /cpus/l2-cache@8)
> sg2042-cpus.dtsi:445.15-464.5: Warning (unique_unit_address_if_enabled): /cpus/cpu@9: duplicate unit-address (also used in node /cpus/l2-cache@9)
> sg2042-cpus.dtsi:466.17-485.5: Warning (unique_unit_address_if_enabled): /cpus/cpu@10: duplicate unit-address (also used in node /cpus/l2-cache@10)
> sg2042-cpus.dtsi:487.17-506.5: Warning (unique_unit_address_if_enabled): /cpus/cpu@11: duplicate unit-address (also used in node /cpus/l2-cache@11)
> sg2042-cpus.dtsi:508.17-527.5: Warning (unique_unit_address_if_enabled): /cpus/cpu@12: duplicate unit-address (also used in node /cpus/l2-cache@12)
> sg2042-cpus.dtsi:529.17-548.5: Warning (unique_unit_address_if_enabled): /cpus/cpu@13: duplicate unit-address (also used in node /cpus/l2-cache@13)
> sg2042-cpus.dtsi:550.17-569.5: Warning (unique_unit_address_if_enabled): /cpus/cpu@14: duplicate unit-address (also used in node /cpus/l2-cache@14)
> sg2042-cpus.dtsi:571.17-590.5: Warning (unique_unit_address_if_enabled): /cpus/cpu@15: duplicate unit-address (also used in node /cpus/l2-cache@15)
>
> Thanks,
> Conor.

I find the rootcause is due to following code in DTS:
```
l2_cache0: l2-cache@0 {
compatible = "cache";
cache-block-size = <64>;
cache-level = <2>;
cache-size = <1048576>;
cache-sets = <1024>;
cache-unified;
};
```
To differ 16 l2-cache controller, we add <unit-address>, but due to
the l2-cache controller on sg2042 has no address, no reg property is
added here. That's why dtbs_check warns "node has a unit name, but no
reg or ranges property". I just double-confirmed with sophgo
engineers, they told me there is really no address for the cache
controller for sg2042.

One solution I use here is to provide unique name for the l2-cache
node. I learn this from "arch/arm64/boot/dts/hisilicon/hi3660.dtsi"
and seems this work and pass dtbs_check with W=1. For example:
```
l2_cache0: l2-cache0 {
compatible = "cache";
cache-block-size = <64>;
cache-level = <2>;
cache-size = <1048576>;
cache-sets = <1024>;
cache-unified;
};

l2_cache1: l2-cache1 {
compatible = "cache";
cache-block-size = <64>;
cache-level = <2>;
cache-size = <1048576>;
cache-sets = <1024>;
cache-unified;
};
......
```
But I remember as mentioned in
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation,
node names should be generic. So I have two questions here:
- Should I use "cache-controller" instead of "l2-cache", though I see
"l2-cache" is used in many places but not listed in
devicetree-specification.
- Even if I replace "l2-cache" with "cache-controller", I think
"cache-controller0", "cache-controller1" ... are not generic name, but
due to sg2042 does not have address for cache controller, how to
handle this problem?