On 08/09/2022 09:45, 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.
It is not clear to me *why* this is needed. Please could you elaborate on the use case of this ? See my questions below.
Signed-off-by: Tao Zhang quic_taozha@quicinc.com
drivers/hwtracing/coresight/coresight-tpdm.c | 32 ++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c index 69ea453..74cc653 100644 --- a/drivers/hwtracing/coresight/coresight-tpdm.c +++ b/drivers/hwtracing/coresight/coresight-tpdm.c @@ -152,6 +152,37 @@ static void tpdm_init_default_data(struct tpdm_drvdata *drvdata) } } +static ssize_t reset_store(struct device *dev,
struct device_attribute *attr,const char *buf,size_t size)
minor nit: Alignment
+{
- int ret = 0;
- unsigned long val;
- struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
- ret = kstrtoul(buf, 10, &val);
So, any integer value written to the sysfs knob triggers the rest ? It may be better to restrict this to "1".
- if (ret)
return ret;- spin_lock(&drvdata->spinlock);
- /* Reset all datasets to ZERO */
- if (drvdata->dsb != NULL)
memset(drvdata->dsb, 0, sizeof(struct dsb_dataset));- /* Init the default data */
- tpdm_init_default_data(drvdata);
Why is this needed ? Does the DSB device configuration change on the fly ?
- spin_unlock(&drvdata->spinlock);
- /* Disable tpdm if enabled */
- if (drvdata->enable)
coresight_disable(drvdata->csdev);
Why is this needed ? Isn't this supposed to be triggered from the "path" when the trace session is complete ?
Suzuki
- return size;
+} +static DEVICE_ATTR_WO(reset);
- /*
- value 1: 64 bits test data
- value 2: 32 bits test data
@@ -192,6 +223,7 @@ static ssize_t integration_test_store(struct device *dev, static DEVICE_ATTR_WO(integration_test); static struct attribute *tpdm_attrs[] = {
- &dev_attr_reset.attr, &dev_attr_integration_test.attr, NULL, };