Hi Ulf, On Tue, Oct 15, 2019 at 02:37:42PM +0200, Ulf Hansson wrote: > On Tue, 1 Oct 2019 at 18:35, Matthias Kaehlcke <m...@chromium.org> wrote: > > > > On Fri, Sep 27, 2019 at 04:42:39AM -0400, Steven Rostedt wrote: > > > On Thu, 26 Sep 2019 15:04:38 -0700 > > > Matthias Kaehlcke <m...@chromium.org> wrote: > > > > > > > Define genpd_power_on/off and genpd_set_performance_state > > > > tracepoints and use them. > > > > > > I agree with Greg about adding a "why" you need this. But, in case > > > there's a good reason to have this, I have comments about the code > > > below. > > > > Thanks Greg and Steven for your comments. > > > > How about this instead: > > > > Add tracepoints for genpd_power_on, genpd_power_off and > > genpd_set_performance_state. The tracepoints can help with > > understanding power domain behavior of a given device, which > > may be particularly interesting for battery powered devices > > and suspend/resume. > > Apologize for the delay, no excuse! > > I don't mind adding trace events, as long as it's for good reasons - > and to me, that seems a bit questionable here. > > According to the above, I believe the information you need is already > available via genpd's debugfs interface, no?
Not in all cases, e.g. you can't peek at sysfs while the device is suspended. Also sysfs doesn't help much with seeing that a PD is toggling between on an off for some (possibly legitimate) reason. At this point I don't need this information badly, just thought it could be useful. No problem if it is decided to hold back on it for now.