On Thu, 21 Jul 2022 at 06:37, Martin Kepplinger <martin.kepplinger@xxxxxxx> wrote: > > If for example the power-domains' power-supply node (regulator) needs > interrupts to work, the current setup with noirq callbacks cannot > work; for example a pmic regulator on i2c, when suspending, usually already > times out during suspend_noirq: > > [ 41.024193] buck4: failed to disable: -ETIMEDOUT > > So fix system suspend and resume for these power-domains by using the > "outer" suspend/resume callbacks instead. Tested on the imx8mq-librem5 board, > but by looking at the dts, this will fix imx8mq-evk and possibly many other > boards too. > > This is designed so that genpd providers just say "this genpd needs > interrupts" (by setting the flag) - without implying an implementation. > > Initially system suspend problems had been discussed at > https://lore.kernel.org/linux-arm-kernel/20211002005954.1367653-8-l.stach@xxxxxxxxxxxxxx/ > which led to discussing the pmic that contains the regulators which > serve as power-domain power-supplies: > https://lore.kernel.org/linux-pm/573166b75e524517782471c2b7f96e03fd93d175.camel@xxxxxxx/T/ > > Signed-off-by: Martin Kepplinger <martin.kepplinger@xxxxxxx> > --- > drivers/base/power/domain.c | 13 +++++++++++++ > include/linux/pm_domain.h | 5 +++++ > 2 files changed, 18 insertions(+) > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > index 5a2e0232862e..ef77700e0def 100644 > --- a/drivers/base/power/domain.c > +++ b/drivers/base/power/domain.c > @@ -130,6 +130,7 @@ static const struct genpd_lock_ops genpd_spin_ops = { > #define genpd_is_active_wakeup(genpd) (genpd->flags & GENPD_FLAG_ACTIVE_WAKEUP) > #define genpd_is_cpu_domain(genpd) (genpd->flags & GENPD_FLAG_CPU_DOMAIN) > #define genpd_is_rpm_always_on(genpd) (genpd->flags & GENPD_FLAG_RPM_ALWAYS_ON) > +#define genpd_irq_on(genpd) (genpd->flags & GENPD_FLAG_IRQ_ON) > > static inline bool irq_safe_dev_in_sleep_domain(struct device *dev, > const struct generic_pm_domain *genpd) > @@ -2079,6 +2080,13 @@ int pm_genpd_init(struct generic_pm_domain *genpd, > genpd->dev_ops.start = pm_clk_resume; > } > > + if (genpd_irq_on(genpd)) { > + genpd->domain.ops.suspend = genpd_suspend_noirq; > + genpd->domain.ops.resume = genpd_resume_noirq; > + genpd->domain.ops.suspend_noirq = NULL; > + genpd->domain.ops.resume_noirq = NULL; Please move this a few lines above, just before we assign the _*noirq callbacks. In this way you don't need to reset thosepointers. > + } > + > /* The always-on governor works better with the corresponding flag. */ > if (gov == &pm_domain_always_on_gov) > genpd->flags |= GENPD_FLAG_RPM_ALWAYS_ON; > @@ -2769,6 +2777,11 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev, > goto err; > dev_gpd_data(dev)->default_pstate = pstate; > } > + > + if (pd->domain.ops.suspend_noirq && (pd->flags & GENPD_FLAG_IRQ_ON)) > + dev_err(dev, "PM domain %s needs irqs but uses noirq suspend\n", > + pd->name); > + This doesn't make sense, as it can never happen according to what we do in pm_genpd_init(). What Lucas suggested in the other thread was to log a warning if a device's (that gets attached to genpd) bus/driver has _*noirq callbacks. That would make sense. Thinking more about this, perhaps we should move to use the _*late/early callbacks instead for genpd. This would decrease the window of potential problematic consumers users (drivers/buses). > return 1; > > err: > diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h > index 76bc9e3ef5ff..03bb86e43550 100644 > --- a/include/linux/pm_domain.h > +++ b/include/linux/pm_domain.h > @@ -61,6 +61,10 @@ > * GENPD_FLAG_MIN_RESIDENCY: Enable the genpd governor to consider its > * components' next wakeup when determining the > * optimal idle state. > + * > + * GENPD_FLAG_IRQ_ON: genpd needs irqs to be able to manage power > + * on/off. Use the outer suspend/resume callbacks > + * instead of noirq for example. > */ > #define GENPD_FLAG_PM_CLK BIT(0) > #define GENPD_FLAG_IRQ_SAFE BIT(1) > @@ -69,6 +73,7 @@ > #define GENPD_FLAG_CPU_DOMAIN BIT(4) > #define GENPD_FLAG_RPM_ALWAYS_ON BIT(5) > #define GENPD_FLAG_MIN_RESIDENCY BIT(6) > +#define GENPD_FLAG_IRQ_ON BIT(7) > > enum gpd_status { > GENPD_STATE_ON = 0, /* PM domain is on */ > -- > 2.30.2 > Kind regards Uffe
