| Message ID | 1438731339-58317-3-git-send-email-lina.iyer@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
On Fri, Aug 21 2015 at 15:04 -0600, Kevin Hilman wrote: >Geert Uytterhoeven <geert@linux-m68k.org> writes: > >> Hi Kevin, >> >> On Fri, Aug 14, 2015 at 7:19 PM, Kevin Hilman <khilman@kernel.org> wrote: >>> On Fri, Aug 14, 2015 at 12:24 AM, Geert Uytterhoeven >>> <geert@linux-m68k.org> wrote: >>>> On Fri, Aug 14, 2015 at 5:40 AM, Kevin Hilman <khilman@kernel.org> wrote: >>>>> Geert Uytterhoeven <geert@linux-m68k.org> writes: >>>>>> On Wed, Aug 12, 2015 at 9:50 PM, Kevin Hilman <khilman@kernel.org> wrote: >>>>>>> This check might have made sense before PM domains, but with PM domains, >>>>>>> it's entirely possible to have a simple device without a driver and the >>>>>>> PM domain handles all the necesary PM, so I think this check >>>>>>> could/should be removed. >>>>>>> >>>>>>> Thoughts? >>>>>> >>>>>> Simple devices without a driver aren't handled automatically. >>>>>> At minimum, the driver should call pm_runtime_enable(), cfr. >>>>>> drivers/bus/simple-pm-bus.c. >>>>> >>>>> That's correct, and in the proof-of-concept stuff I hacked up and in >>>>> Lina's series, the CPU "devices" do indeed to this. Without that, they >>>>> wouldn't end up ever taking this codepath through genpd's >>>>> runtime_suspend and power_off hooks. >>>>> >>>>> Also, I'm not sure if your comment was meant to be an objection to the >>>>> patch? or if you're OK with it. >>>> >>>> My comment was purely meant as a response to "it's entirely possible to have a >>>> simple device without a driver and the PM domain handles all the necesary PM". >>> >>> Right, so if the PM domain does the pm_runtime_enable() for these >>> "simple" devices without drivers, they can still exist without a >>> driver, and the PM domain doing all the magic. >> >> Is it possible to let the PM Domain do the pm_runtime_enable() itself in >> the absence of a driver? > >Well, I suppose it's possible, not sure it's recommended. :) > >> If yes, I wouldn't have needed simple-pm-bus.c. >> What if a driver is bound later? > >Yeah, you're approach is better. > I am not sure I understand the approach? Initialize the CPU devices as "simple-pm-bus" compatible? Thanks, Lina -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 5 August 2015 at 01:35, Lina Iyer <lina.iyer@linaro.org> wrote: > Remove check for driver of a device, for runtime PM. Device may be > suspended without an explicit driver. This check seems to be vestigial > and incorrect in the current context. > > Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> > Signed-off-by: Kevin Hilman <khilman@linaro.org> > Signed-off-by: Lina Iyer <lina.iyer@linaro.org> I think this makes perfect sense! Moreover in *theory*, I have considered both cases for how a device currently gets attached/detached to its genpd and I can't find any issues with $subject patch. With *both* cases I mean attaching the device using *pm_genpd_[name]add_device() API or via the ->probe() sequence using the dev_pm_domain_attach() API. Now, of course that statement also relies on that drivers behaves properly from a runtime PM point of view, for example make sure to do pm_runtime_disable() at ->remove(). Acked-by: Ulf Hansson <ulf.hansson@linaro.org> Kind regards Uffe > --- > drivers/base/power/domain.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > index 5fd1306..ef8d19f 100644 > --- a/drivers/base/power/domain.c > +++ b/drivers/base/power/domain.c > @@ -394,8 +394,7 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd) > if (stat > PM_QOS_FLAGS_NONE) > return -EBUSY; > > - if (pdd->dev->driver && (!pm_runtime_suspended(pdd->dev) > - || pdd->dev->power.irq_safe)) > + if (!pm_runtime_suspended(pdd->dev) || pdd->dev->power.irq_safe) > not_suspended++; > } > > -- > 2.1.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 5fd1306..ef8d19f 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -394,8 +394,7 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd) if (stat > PM_QOS_FLAGS_NONE) return -EBUSY; - if (pdd->dev->driver && (!pm_runtime_suspended(pdd->dev) - || pdd->dev->power.irq_safe)) + if (!pm_runtime_suspended(pdd->dev) || pdd->dev->power.irq_safe) not_suspended++; }