Messages in this thread | | | Date | Tue, 23 May 2023 15:53:06 +0100 | Subject | Re: [PATCH v4 04/11] coresight-tpdm: Add reset node to TPDM node | From | Suzuki K Poulose <> |
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On 27/04/2023 10:00, 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> > --- > .../ABI/testing/sysfs-bus-coresight-devices-tpdm | 10 ++++++++ > drivers/hwtracing/coresight/coresight-tpdm.c | 27 ++++++++++++++++++++++ > 2 files changed, 37 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > index 4a58e64..686bdde 100644 > --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > @@ -11,3 +11,13 @@ Description: > Accepts only one of the 2 values - 1 or 2. > 1 : Generate 64 bits data > 2 : Generate 32 bits data > + > +What: /sys/bus/coresight/devices/<tpdm-name>/reset > +Date: March 2023 > +KernelVersion 6.3 > +Contact: Jinlong Mao (QUIC) <quic_jinlmao@quicinc.com>, Tao Zhang (QUIC) <quic_taozha@quicinc.com> > +Description: > + (Write) Reset the dataset of the tpdm, and disable the tpdm. > + > + Accepts only one value - 1. > + 1 : Reset the dataset of the tpdm > diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c > index 6f8a8ab..2e64cfd 100644 > --- a/drivers/hwtracing/coresight/coresight-tpdm.c > +++ b/drivers/hwtracing/coresight/coresight-tpdm.c > @@ -164,6 +164,32 @@ static int tpdm_datasets_setup(struct tpdm_drvdata *drvdata) > return 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); > + tpdm_reset_datasets(drvdata); > + > + spin_unlock(&drvdata->spinlock); > + > + /* Disable tpdm if enabled */ > + if (drvdata->enable) > + coresight_disable_source(drvdata->csdev, NULL);
I am not really keen on doing this behind the back. What about the path of components ? We could simply reject the request when the TPDA is enabled and let the user alway follow : 1) Disable the TPDM manually via sysfs 2) Reset the TPDM.
So, please remove the disable step here.
Suzuki
> + > + return size; > +} > +static DEVICE_ATTR_WO(reset); > + > /* > * value 1: 64 bits test data > * value 2: 32 bits test data > @@ -204,6 +230,7 @@ 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, > };
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