Re: [PATCH v2 1/3] coresight: catu: Introduce refcount and spinlock for enabling/disabling

[Leo Yan]

Hi Yabin,

On Tue, Apr 01, 2025 at 06:21:59PM -0700, Yabin Cui wrote:

[...]

> > @@ -486,12 +491,17 @@ static int catu_disable_hw(struct catu_drvdata *drvdata)
> >
> >  static int catu_disable(struct coresight_device *csdev, void *__unused)
> >  {
> > -       int rc;
> > +       int rc = 0;
> >         struct catu_drvdata *catu_drvdata = csdev_to_catu_drvdata(csdev);
> > +       guard(raw_spinlock_irqsave)(&catu_drvdata->spinlock);
> >
> > -       CS_UNLOCK(catu_drvdata->base);
> > -       rc = catu_disable_hw(catu_drvdata);
> > -       CS_LOCK(catu_drvdata->base);
> > +       if (--csdev->refcnt == 0) {
> > +               CS_UNLOCK(catu_drvdata->base);
> > +               rc = catu_disable_hw(catu_drvdata);
> > +               CS_LOCK(catu_drvdata->base);
> > +       } else {
> > +               rc = -EBUSY;

This is not an error if the decremented reference counter is not zero.
It should return 0.  Otherwise, the change looks good to me.

Thanks,
Leo