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Message-ID: <aa2b93f2-9916-bcf1-4d5f-dc749fe2944e@arm.com>
Date:   Mon, 24 Oct 2022 11:02:13 +0100
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Subject: Re: [PATCH 3/9] coresight-tpdm: Initialize DSB subunit configuration
To:     Tao Zhang <quic_taozha@quicinc.com>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Konrad Dybcio <konradybcio@gmail.com>,
        Mike Leach <mike.leach@linaro.org>
Cc:     Jinlong Mao <quic_jinlmao@quicinc.com>,
        Leo Yan <leo.yan@linaro.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org,
        Tingwei Zhang <quic_tingweiz@quicinc.com>,
        Yuanfang Zhang <quic_yuanfang@quicinc.com>,
        Trilok Soni <quic_tsoni@quicinc.com>,
        Hao Zhang <quic_hazha@quicinc.com>,
        linux-arm-msm@vger.kernel.org, bjorn.andersson@linaro.org
References: <1662626705-13097-1-git-send-email-quic_taozha@quicinc.com>
 <1662626705-13097-4-git-send-email-quic_taozha@quicinc.com>
From:   Suzuki K Poulose <suzuki.poulose@arm.com>
In-Reply-To: <1662626705-13097-4-git-send-email-quic_taozha@quicinc.com>
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Hi

On 08/09/2022 09:44, Tao Zhang wrote:
> DSB subunit need to be configured in enablement and disablement.
> A struct that specifics associated to dsb dataset is needed. It
> saves the configuration and parameters of the dsb datasets. This
> change is to add this struct and initialize the configuration of
> DSB subunit.
> 
> Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
> ---
>   drivers/hwtracing/coresight/coresight-tpdm.c | 44 ++++++++++++++++++++++++++--
>   drivers/hwtracing/coresight/coresight-tpdm.h | 17 +++++++++++
>   2 files changed, 58 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
> index 88df3e6..69ea453 100644
> --- a/drivers/hwtracing/coresight/coresight-tpdm.c
> +++ b/drivers/hwtracing/coresight/coresight-tpdm.c
> @@ -24,6 +24,22 @@ static void tpdm_enable_dsb(struct tpdm_drvdata *drvdata)
>   {
>   	u32 val;
>   
> +	val = readl_relaxed(drvdata->base + TPDM_DSB_TIER);
> +	/* Set trigger timestamp */
> +	if (drvdata->dsb->trig_ts)

What happens if this instance doesn't have a DSB set ? Have
you tested this on a system without the DSB ?

Suzuki