RE: [EXT] Re: [PATCH v4 2/6] perf: imx_perf: refactor driver for imx93

[Xu Yang]

Hi Will,

> 
> 
> On Wed, Jan 31, 2024 at 01:58:07PM +0800, Xu Yang wrote:
> > This driver is initinally used to support imx93 Soc and now it's time to
> > add support for imx95 Soc. However, some macro definitions and events are
> > different on these two Socs. For preparing imx95 supports, this will
> > refactor driver for imx93.
> >
> > Signed-off-by: Xu Yang <xu.yang_2@xxxxxxx>
> >
> > ---
> > Changes in v4:
> >  - new patch
> > ---
> >  drivers/perf/fsl_imx9_ddr_perf.c | 121 ++++++++++++++++++++++---------
> >  1 file changed, 87 insertions(+), 34 deletions(-)
> 
> [...]
> 
> > @@ -476,12 +490,12 @@ static int ddr_perf_event_add(struct perf_event *event, int flags)
> >       hwc->idx = counter;
> >       hwc->state |= PERF_HES_STOPPED;
> >
> > +     /* read trans, write trans, read beat */
> > +     imx93_ddr_perf_monitor_config(pmu, cfg, cfg1, cfg2);
> > +
> >       if (flags & PERF_EF_START)
> >               ddr_perf_event_start(event, flags);
> >
> > -     /* read trans, write trans, read beat */
> > -     ddr_perf_monitor_config(pmu, cfg, cfg1, cfg2);
> > -
> >       return 0;
> 
> This change looks like more than just refactoring and should probably be a
> separate patch. Is it a bug fix for the existing code?

Yes, I found the order has an impact. I will create a patch for it.

> 
> > +static int ddr_perf_add_events(struct ddr_pmu *pmu)
> > +{
> > +     int i, ret;
> > +     struct attribute **attrs = pmu->devtype_data->attrs;
> > +     struct device *pmu_dev = pmu->pmu.dev;
> > +
> > +     if (!attrs)
> > +             return 0;
> > +
> > +     for (i = 0; attrs[i]; i++) {
> > +             ret = sysfs_add_file_to_group(&pmu_dev->kobj, attrs[i], "events");
> > +             if (ret) {
> > +                     dev_warn(pmu->dev, "i.MX9 DDR Perf add events failed (%d)\n", ret);
> > +                     return ret;
> 
> Can you use the '.is_visible' callback in 'struct attribute_group' to avoid
> having to manipulate sysfs directly like this? For example, create separate
> groups for the imx93 and imx95-specific events and only make them visible
> if we're on the appropriate hardware.

Yes, I will try your suggestion.

Thanks,
Xu Yang