linux-kernel - Re: [PATCH v1 2/3] coresight: tpdm: add static tpdm support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4a28c9ea-fe71-44de-ada9-eda3111eff9e@oss.qualcomm.com>
Date: Wed, 3 Sep 2025 13:06:37 +0200
From: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
To: Jie Gan <jie.gan@....qualcomm.com>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Mike Leach
 <mike.leach@...aro.org>,
        James Clark <james.clark@...aro.org>, Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley <conor+dt@...nel.org>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Tingwei Zhang <tingwei.zhang@....qualcomm.com>,
        Mao Jinlong <jinlmao.mao@....qualcomm.com>,
        Tao Zhang <quic_taozha@...cinc.com>
Cc: linux-arm-msm@...r.kernel.org, coresight@...ts.linaro.org,
        linux-arm-kernel@...ts.infradead.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1 2/3] coresight: tpdm: add static tpdm support

On 8/22/25 12:30 PM, Jie Gan wrote:
> The static TPDM function as a dummy source, however, it is essential
> to enable the port connected to the TPDA and configure the element size.
> Without this, the TPDA cannot correctly receive trace data from the
> static TPDM. Since the static TPDM does not require MMIO mapping to
> access its registers, a clock controller is not mandatory for its
> operation.
> 
> Signed-off-by: Jie Gan <jie.gan@....qualcomm.com>
> ---
>  drivers/hwtracing/coresight/coresight-tpda.c |   9 ++
>  drivers/hwtracing/coresight/coresight-tpdm.c | 148 ++++++++++++++-----
>  drivers/hwtracing/coresight/coresight-tpdm.h |   8 +
>  3 files changed, 131 insertions(+), 34 deletions(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/hwtracing/coresight/coresight-tpda.c
> index 333b3cb23685..4e93fa5bace4 100644
> --- a/drivers/hwtracing/coresight/coresight-tpda.c
> +++ b/drivers/hwtracing/coresight/coresight-tpda.c
> @@ -68,6 +68,15 @@ static int tpdm_read_element_size(struct tpda_drvdata *drvdata,
>  	int rc = -EINVAL;
>  	struct tpdm_drvdata *tpdm_data = dev_get_drvdata(csdev->dev.parent);
>  
> +	if (coresight_is_static_tpdm(csdev)) {
> +		rc = fwnode_property_read_u32(dev_fwnode(csdev->dev.parent),
> +					      "qcom,dsb-element-bits", &drvdata->dsb_esize);
> +		rc &= fwnode_property_read_u32(dev_fwnode(csdev->dev.parent),
> +					       "qcom,cmb-element-bits", &drvdata->cmb_esize);

This allows either pass/pass or fail/pass combinations to succeed
- is this intended?

Konrad