Re: [PATCH] coresight: dynamic-replicator: Fix handling of multiple connections

From: Sai Prakash Ranjan
Date: Tue May 19 2020 - 05:04:20 EST


Hi Mike, Suzuki,

On 2020-05-16 15:34, Sai Prakash Ranjan wrote:
Hi Mike, Suzuki

[...]


Please look at the CoreSight components specification 3.0 (ARM IHI
0029E) Section B2.1.2 which describes the Unique Component Identifier
(UCI).
As mentioned above this consists of a combination of bits from
multiple registers, including PIDR4.


Ok got it now, thanks for clearing the doubt. I will go ahead with
this method to identify QCOM impl and post a patch.


Looking some more into this, since we have this limitation only on
specific replicator on very few QCOM SoCs, rather than having a blanket
workaround for all QCOM, we were thinking it would be better to have
this workaround based on a firmware property something like
"qcom,replicator-loses-context" for those replicators with this
limitation and then set the drvdata->check_idfilter_val based on
this property.


Sorry for going back and forth on this one, but I think having a firmware
property will clearly help us identify the issue on specific SoCs rather than
wholesale workaround for all QCOM SoCs. For now, I will post a patch based on
the property "qcom,replicator-loses-context", please feel free to yell at me
if this is completely wrong and we can discuss it further in that patch.

Thanks,
Sai

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