Re: [PATCH v3 04/11] coresight-tpdm: Add reset node to TPDM node

Suzuki K Poulose
2023-03-23T14:41:37Z

On 23/03/2023 06:04, Tao Zhang wrote:
> TPDM device need a node to reset the configurations and status of
> it. This change provides a node to reset the configurations and
> disable the TPDM if it has been enabled.
>
> Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
> ---
> drivers/hwtracing/coresight/coresight-tpdm.c | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
> index 5e1e2ba..104638d 100644
> --- a/drivers/hwtracing/coresight/coresight-tpdm.c
> +++ b/drivers/hwtracing/coresight/coresight-tpdm.c
> @@ -161,6 +161,33 @@ static void tpdm_datasets_setup(struct tpdm_drvdata *drvdata)
> drvdata->datasets |= pidr & GENMASK(TPDM_DATASETS - 1, 0);
> }
>
> +static ssize_t reset_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf,
> + size_t size)
> +{
> + int ret = 0;
> + unsigned long val;
> + struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +
> + ret = kstrtoul(buf, 10, &val);
> + if (ret || val != 1)
> + return -EINVAL;
> +
> + spin_lock(&drvdata->spinlock);
> + /* Reset all datasets to ZERO, and init the default data*/
> + tpdm_init_datasets(drvdata);

With the suggested rename in the previous patch, you wouldn't need
a comment here.

> +
> + spin_unlock(&drvdata->spinlock);
> +

> + /* Disable tpdm if enabled */
> + if (drvdata->enable)
> + coresight_disable(drvdata->csdev);

Couldn't this be done via disable_source ? Please don't overload
the sysfs handle.

> +
> + return size;
> +}
> +static DEVICE_ATTR_WO(reset);

Documentation for the sysfs node please ?

Suzuki