Re: [v3] PCI: cadence: Fix sending message with data or without data

[Hans Zhang <18255117159@163.com>]

On 2025/2/14 23:31, Manivannan Sadhasivam wrote:
> On Fri, Feb 14, 2025 at 10:28:11PM +0800, Hans Zhang wrote:
>> Sorry Mani, I shouldn't have spread this SOC bug. This is a bug in RTL
>> design, the WSTRB signal of AXI bus is not connected correctly, so the first
>> generation SOC cannot send message, because we mainly use RC mode, and we
>> cannot send PME_Turn_OFF, that is, our SOC does not support L2. I have no
>> choice about this, I entered the company relatively late, and our SOC has
>> already TO.
> 
> Ok. Just to clear my head, this patch is needed irrespective of the hw issue,
> right? And with or without this patch, first revision hw cannot send any MSG
> TLPs?

Yes, that was a problem with our own SOC design, the Cadence RTL bug.	

> If so, it is fine. But is there a way we could detect those first generation IPs
> and flag it to users about broken MSG TLP support? Atleast, that would make the
> users aware of broken hw.

I don't know how to do it, but here are the questions that were actually 
tested.

>>
>> This patch is to solve the Cadence common code bug, and does not conform to
>> Cadence documentation.
> 
> you mean 'does'?
> 

What I mean is that common code bit16=1 is to send a message without 
data, while Cadence's development document says that bit16=0 is to send 
a message without data. This is not consistent with the documentation 
description, and the final verification results, the development 
documentation described is correct.

Best regards
Hans