linux-kernel - Re: [PATCH V1 0/1] soc: qcom: dcc: Add QAD, Cti-trigger and Bootconfig support for Data Capture and Compare(DCC)

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Message-ID: <20230109151818.hxpi2nleb53ibv7w@builder.lan>
Date:   Mon, 9 Jan 2023 09:18:18 -0600
From:   Bjorn Andersson <andersson@...nel.org>
To:     Souradeep Chowdhury <quic_schowdhu@...cinc.com>
Cc:     Andy Gross <agross@...nel.org>,
        Konrad Dybcio <konrad.dybcio@...ainline.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Alex Elder <elder@...e.org>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-arm-msm@...r.kernel.org,
        Sai Prakash Ranjan <quic_saipraka@...cinc.com>,
        Sibi Sankar <quic_sibis@...cinc.com>,
        Rajendra Nayak <quic_rjendra@...cinc.com>, vkoul@...nel.org
Subject: Re: [PATCH V1 0/1] soc: qcom: dcc: Add QAD, Cti-trigger and
 Bootconfig support for Data Capture and Compare(DCC)

On Mon, Jan 09, 2023 at 07:32:25PM +0530, Souradeep Chowdhury wrote:
> This patch adds the Bootconfig, QAD and CTI-Trigger support for DCC.
> 

As with the other patch, please move your motivation into the commit
message of the patch.

That said, this seems to be 3 different topics, and hence should be
three different patches.

> 1.Bootconfig
> 
> Bootconfig parser has been added to DCC driver so that the register addresses
> can be configured during boot-time. This is used to debug crashes that can happen
> during boot-time. The expected format of a bootconfig is as follows:-
> 
> dcc_config {
> 	link_list_0 {
> 		qcom-curr-link-list = <The list number to configure>
> 		qcom-link-list =  <Address as same format as dcc separated by '_'>,
> 	}
> }
> 
> Example:
> 
> dcc_config {
> 	link_list_0 {

The name of the node does not seem to have any significance; this could
be nice to mention. I also think it would set a good precedence if you
used the number of the qcom-curr-link-list in the node name, rather than
just an iterator...

> 		qcom-curr-link-list = 6
> 		qcom-link-list = R_0x1781005c_1_apb,
> 				 R_0x1782005c_1_apb
> 	}
> 	link_list_1 {
> 		qcom-curr-link-list = 5
> 		qcom-link-list = R_0x1784005c_1_apb
> 	}
> }
> 
> 2.QAD
> 
> QAD can be enabled as a part of debugfs file under each individual list folder.
> QAD is used to specify the access control for DCC configurations, on enabling
> it the access control to dcc configuration space is restricted.
> 

Who is locked out from this restricted access? Please mention why this
is a good thing.

> 3.CTI-trigger
> 
> CTI trigger is used to enable the Cross trigger interface for DCC. On enabling
> CTI trigger the dcc software trigger can be done by writing to CTI trig-out.
> Also the hwtrigger debugfs file is created which needs to be disabled for enabling
> CTI-trigger.
> 

Please mention why hwtrigger needs to be disabled, and why does it need
to be disabled?

> Changes in V1
> 
> *Fixed the W=1 warnings in V0 of the patch

Please follow the standard practice of giving your first version of a
patch version 1.

Thanks,
Bjorn

> 
> Souradeep Chowdhury (1):
>   soc: qcom: dcc: Add QAD, Ctitrigger and Bootconfig support for DCC
> 
>  Documentation/ABI/testing/debugfs-driver-dcc |  24 +++
>  drivers/soc/qcom/dcc.c                       | 284 ++++++++++++++++++++++++++-
>  2 files changed, 304 insertions(+), 4 deletions(-)
> 
> --
> 2.7.4
>