Re: [PATCH v5 3/3] arm: dts: ti: Add device tree support for PRU-ICSS on AM335x

[Parvathi Pudi <parvathi@couthit.com>]

Hi,

> On 16/03/2026 13:00, Parvathi Pudi wrote:
>> Hi,
>> 
>>> Parvathi Pudi <parvathi@couthit.com> writes:
>>>
>>>> From: Roger Quadros <rogerq@ti.com>
>>>>
>>>> The TI Sitara AM335x ICE-V2 consists of single PRU-ICSS instance,
>>>> This patch adds the new device tree overlay file in-order to enable
>>>> PRU-ICSS instance, along with makefile changes.
>>>>
>>>> PRU-ICSS instance consists of two PRU cores along with various
>>>> peripherals such as the Interrupt Controller (PRU_INTC), the Industrial
>>>> Ethernet Peripheral(IEP), the Real Time Media Independent Interface
>>>> controller (MII_RT), and the Enhanced Capture (eCAP) event module.
>>>>
>>>> am33xx-l4.dtsi - Adds IEP and eCAP peripheral as child nodes
>>>> of the PRUSS subsystem node.
>>>>
>>>> am335x-icev2-prueth.dtso - Adds PRU-ICSS instance node along with PRU
>>>> eth port information and corresponding port configuration. It includes
>>>> interrupt mapping for packet reception, HW timestamp collection, and PRU
>>>> Ethernet ports in MII mode,
>>>>
>>>> GPIO configuration, boot strapping along with delay configuration for
>>>> individual PRU Ethernet port and other required nodes.
>>>>
>>>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>>>> Signed-off-by: Andrew F. Davis <afd@ti.com>
>>>> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
>>>> Signed-off-by: Basharath Hussain Khaja <basharath@couthit.com>
>>>> Signed-off-by: Parvathi Pudi <parvathi@couthit.com>
>>>
>>> [...]
>>>
>>>> +/*
>>>> + * Disable CPSW switch node and
>>>> + * MDIO configuration to prevent
>>>> + * conflict with PRU-ICSS
>>>> + */
>>>> +&mac_sw {
>>>> +        status = "disable";
>>>> +};
>>>> +
>>>> +&davinci_mdio_sw {
>>>> +        status = "disable";
>>>> +};
>>>
>>> I think you need s/disable/disabled/?  (note the trailing 'd').  Without
>>> that, I don't think you're disabling these nodes, so I'm curious how it
>>> is not conflicting with the PRU-ICSS.
>>>
>>> Kevin
>> 
>> Thank you for pointing out this typo.
>> 
>> We checked the kernel code as to why this did not create any issue in our
>> testing.  We found that the device availability check goes through
>> of_device_is_available(), which only treats "ok" or "okay" as enabled.
>> Anything else is effectively treated as not enabled.
>> 
>> So even though "disable" isn't the usual DT value, it still prevents the
>> node from being probed since it doesn't match "ok"/"okay".
> 
> 
> The question is whether you build tested your code (so dtbs_check). And
> if not, why?
> 

We did run dtbs_check as part of our internal testing workflow. However, it
is executed within a test framework that runs multiple checks together and is
currently trimming part of the dtbs_check output. Because of this, the schema
validation warning for "disable" was not visible in the logs we reviewed
and we missed catching this error. 

We have verified that dtbs_check does report this issue, and we will update
our test setup to retain full dtbs_check output to avoid missing such warnings
in the future.

Thanks and Regards,
Parvathi.