Re: [PATCH v4 03/15] coresight: Register CPU PM notifier in core layer

[Leo Yan <leo.yan@arm.com>]

On Tue, Nov 11, 2025 at 12:13:38PM +0000, Suzuki Kuruppassery Poulose wrote:

[...]

> > --- a/drivers/hwtracing/coresight/coresight-core.c
> > +++ b/drivers/hwtracing/coresight/coresight-core.c

> > +static int coresight_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd,
> > +				   void *v)
> > +{
> > +	unsigned int cpu = smp_processor_id();
> > +	struct coresight_device *source = per_cpu(csdev_source, cpu);
> > +
> > +	if (!coresight_pm_is_needed(source))
> > +		return NOTIFY_OK;
> > +
> > +	switch (cmd) {
> > +	case CPU_PM_ENTER:
> > +		if (coresight_pm_save(source))
> 
> Unless we do the "set_per_cpu_source" *ON the CPU*, what guarantees that
> this will vanish while we do the PM save ? e.g., UNLOAD coresight_etm4x
> driver

Good catch!  I will use SMP call to set per CPU source in next version.

Thanks,
Leo