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

[Suzuki K Poulose]

On 23/03/2023 14:41, Suzuki K Poulose wrote:
> 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.

Please justify why this "do everything" magic knob is required
when there are tunables for individual controls in the later
patches.

Suzuki

> > Signed-off-by: Tao Zhang <quic_taozha@xxxxxxxxxxx>
> > ---
> >   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