[PATCH 4/4] arch: arm64: ti: Add support for J784s4 EVM board

Vignesh Raghavendra vigneshr at ti.com
Wed Aug 24 02:15:08 PDT 2022



On 24/08/22 12:42, Krzysztof Kozlowski wrote:
> On 24/08/2022 08:33, Vignesh Raghavendra wrote:
>> Hi Krzysztof,
>>
>> On 24/08/22 10:36, Nishanth Menon wrote:
>>> On 13:21-20220823, Krzysztof Kozlowski wrote:
>>>>> +
>>>>> +/ {
>>>>> +	compatible = "ti,j784s4-evm", "ti,j784s4";
>>>>> +	model = "Texas Instruments J784S4 EVM";
>>>>> +
>>>>> +	chosen {
>>>>> +		stdout-path = "serial2:115200n8";
>>>>> +		bootargs = "console=ttyS2,115200n8 earlycon=ns16550a,mmio32,0x2880000";
>>>>
>>>> earlycon is not a property of hardware. Console is defined in
>>
>> earlycon is helpful for debugging early crashes. How is it any different
>> from "console =" property as described in
>> Documentation/devicetree/usage-model.rst?
> 
> choice of console is needed for basic operation and is chosen based on
> current hardware setup. earlycon is purely for debugging and should be
> enabled only when debugging is intended, not on mainline wide-available
> sources.
> 
>>
>>>> stdout-path, so please drop entire bootargs.
>>>
>>> We will probably have to cleanup elsewhere as well - point noted.
>>>
>>
>> Whats the alternative to pass default bootargs to kernel if bootloader
>> does not pass bootargs via cmdline? I see quite a few dts file use
>> bootargs = "earlycon" at least
> 
> Uboot, your own out-of-tree testing patches? What's the point to have
> earlycon available for every user which does not want to debug?
> 
> Sorry, but bootargs are not accepted in DTS. We have several discussions
> around it over time...

Understood, just wanted to make sure what the latest stance is, as I see
lot of files in arm64 dts folder still use bootargs and earlycon. Thanks
for the clarification!

-- 
Regards
Vignesh



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