Re: [PATCH 3/9] coresight-tpdm: Initialize DSB subunit configuration

[Suzuki K Poulose <suzuki.poulose@arm.com>]

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