[PATCH v6 01/19] coresight: sysfs: Validate CPU online status for per-CPU sources

[Leo Yan]

On Mon, Mar 16, 2026 at 02:28:35PM +0000, Suzuki K Poulose wrote:

[...]

> > > e.g., add a flag in the coresight_desc.flags = CORESIGHT_DESC_CPU_BOUND
> > > 
> > > and then desc.cpu describes the associated CPU. Otherwise, defaults to -1.
> > > That way you could restrict the changes to only those that need the
> > > CPU (ETMx and CTIs ?) Also makes any new driver safe.
> > 
> > Instead of adding a flag, I'd use a helper to check existed flags:
> > 
> >    static inline bool coresight_is_cpu_bound(struct coresight_device *csdev)
> >    {
> >           if (!csdev)
> >                   return false;
> > 
> >           if (coresight_is_percpu_source(csdev))
> >                   return true;
> > 
> >           if (csdev->type == CORESIGHT_DEV_TYPE_HELPER &&
> >               csdev->subtype.helper_subtype == CORESIGHT_DEV_SUBTYPE_HELPER_ECT_CTI)
> 
> That works, but if a new device type comes in, we may have to expand the
> list. Having a flag makes much more sense and the core driver only does
> what has been asked for. I prefer the flags.

Sure, I will add a new flag.  Thanks!