Re: [PATCH v3 1/3] dt-bindings: i3c: xlnx: Add IBI and hot-join capability properties

["Patil, Shubham Sanjay" <shubpati@amd.com>]

Hi Frank,

On 10/21/2026 8:43 PM, Frank Li wrote:
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> 
> 
> On Wed, Oct 21, 2026 at 09:06:50AM +0200, Michal Simek wrote:
>> Hi Rob,
>>
>> On 10/7/26 08:03, Patil, Shubham Sanjay wrote:
>>> Hi Rob, Just a reminder !
>>
>> <snip>
>>
>>>>>>>> No reason to keep hj because the difference between HJ and IBI is the
>>>>>>>> address when address arbitration. If hardware support IBI, it should support
>>>>>>>> HJ. HJ just use special address 0x2.
>>>>>>>
>>>>>>> For this IP, they appear to be controlled by different configuration time
>>>>>>> parameters, so I don't think conflating the two is the right thing to do
>>>>>>> here:
>>>>>>> https://docs.amd.com/r/en-US/pg439-axi-i3c/Configuration-Tab
>>>>>>> Per this doc, and the original commit, hotjoin configuration is not
>>>>>>> permitted when ibi is not supported but can be enabled and disabled
>>>>>>> separately when it is.
>>>>>>
>>>>>> I am not sure why provide such flexiblity, only difference is that compare
>>>>>> address 2 or other value.
>>>>>
>>>>> It's not unusual for FPGA IPs to provide extreme flexibility so that the
>>>>> consumption of resources can be kept to a minimum, often to the point of
>>>>> excessiveness. E.g. for a ethernet MAC IP each individual statistic might
>>>>> have a configuration option.
>>>>>
>>>>>>
>>>>>> This feature may be quite common for i3c, if other soft IP provider such
>>>>>> flexiblity, still common property is the better than vendor specific one.
>>>>>
>>>>> I'm not at all in favour of speculatively adding properties for
>>>>> configuration properties of FPGA IPs, particularly given the likelihood
>>>>> of abuse by others. Without multiple demonstrated users, things shouldn't
>>>>> be considered for being made common anyway.
>>>>
>>>> Rob:
>>>>           What's your opinion? I predict we will met similar problem when
>>>> I3C become popluar.
>>>>           Do you perfer use vendor property fistly or direct add common
>>>> property?
>>>>           There will be back compatible problem if change vendor property to
>>>> common property.
>>>>
>>>> Frank
>>
>> It looks like this thread is stuck and everybody is waiting for your opinion
>> about it. Can you please take a look when you have time?
> 
> I suggest make a version, which support all enable/disable IBI/HJ. We can
> discuss later. I think less possible to config two difference instance at
> one SoC.
> 
> Frank

My understanding is that the next version should support both enabling 
and disabling In-Band Interrupt, and both enabling and disabling Hot-Join.

For compatible "xlnx,axi-i3c-1.0", both features are enabled by default. 
A device-tree property is needed only to force a feature off on one 
controller instance. I will not use xlnx,in-band-interrupt-capable or 
xlnx,hot-join-capable. The case of two instances on one SoC with 
different synthesis options can be discussed later.

Please correct me if this is not what you meant.

Thanks,
Shubham

> 
>>
>> Thanks,
>> Michal
>>