| Message ID | 20200811190252.10559-1-sibis@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] PM / Domains: Add GENPD_FLAG_SUSPEND_ON flag | expand |
Hi, On Tue, Aug 11, 2020 at 12:03 PM Sibi Sankar <sibis@codeaurora.org> wrote: > > This is for power domains which needs to stay powered on for suspend > but can be powered on/off as part of runtime PM. This flag is aimed at > power domains coupled to remote processors which enter suspend states > independent to that of the application processor. Such power domains > are turned off only on remote processor crash/shutdown. > > Signed-off-by: Sibi Sankar <sibis@codeaurora.org> > --- > drivers/base/power/domain.c | 3 ++- > include/linux/pm_domain.h | 5 +++++ > 2 files changed, 7 insertions(+), 1 deletion(-) Seems sane to me. Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Douglas Anderson <dianders@chromium.org>
Quoting Sibi Sankar (2020-08-11 12:02:51) > diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h > index ee11502a575b0..3002a2d68936a 100644 > --- a/include/linux/pm_domain.h > +++ b/include/linux/pm_domain.h > @@ -55,6 +55,10 @@ > * > * GENPD_FLAG_RPM_ALWAYS_ON: Instructs genpd to always keep the PM domain > * powered on except for system suspend. > + * > + * GENPD_FLAG_SUSPEND_ON: Instructs genpd to keep the PM domain powered > + * on during suspend and runtime PM controlled Maybe, "powered on across system suspend (if it is already powered on)" to match the hunk above that talks about system suspend for GENPD_FLAG_RPM_ALWAYS_ON. Otherwise someone may think that this powers on the genpd during suspend or powers it on during runtime suspend. > + * otherwise. > */ > #define GENPD_FLAG_PM_CLK (1U << 0) > #define GENPD_FLAG_IRQ_SAFE (1U << 1)
Sibi Sankar <sibis@codeaurora.org> writes: > This is for power domains which needs to stay powered on for suspend > but can be powered on/off as part of runtime PM. This flag is aimed at > power domains coupled to remote processors which enter suspend states > independent to that of the application processor. Such power domains > are turned off only on remote processor crash/shutdown. > > Signed-off-by: Sibi Sankar <sibis@codeaurora.org> Seems like a useful use-case, but i think there should be a bit more description/documentation about what is the expected/desired behavior during system suspsend when a power-domain with this flag is already runtime-PM suspended. Similarily, on system resume, what is the expected/desired behavior? Kevin
On Tue, 11 Aug 2020 at 21:03, Sibi Sankar <sibis@codeaurora.org> wrote: > > This is for power domains which needs to stay powered on for suspend > but can be powered on/off as part of runtime PM. This flag is aimed at > power domains coupled to remote processors which enter suspend states > independent to that of the application processor. Such power domains > are turned off only on remote processor crash/shutdown. As Kevin also requested, please elaborate more on the use case. Why exactly must the PM domain stay powered on during system suspend? Is there a wakeup configured that needs to be managed - or is there a co-processor/FW behaviour that needs to be obeyed to? Kind regards Uffe > > Signed-off-by: Sibi Sankar <sibis@codeaurora.org> > --- > drivers/base/power/domain.c | 3 ++- > include/linux/pm_domain.h | 5 +++++ > 2 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > index 2cb5e04cf86cd..ba78ac4a450d4 100644 > --- a/drivers/base/power/domain.c > +++ b/drivers/base/power/domain.c > @@ -129,6 +129,7 @@ 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_is_suspend_on(genpd) (genpd->flags & GENPD_FLAG_SUSPEND_ON) > > static inline bool irq_safe_dev_in_no_sleep_domain(struct device *dev, > const struct generic_pm_domain *genpd) > @@ -949,7 +950,7 @@ static void genpd_sync_power_off(struct generic_pm_domain *genpd, bool use_lock, > { > struct gpd_link *link; > > - if (!genpd_status_on(genpd) || genpd_is_always_on(genpd)) > + if (!genpd_status_on(genpd) || genpd_is_always_on(genpd) || genpd_is_suspend_on(genpd)) > return; > > if (genpd->suspended_count != genpd->device_count > diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h > index ee11502a575b0..3002a2d68936a 100644 > --- a/include/linux/pm_domain.h > +++ b/include/linux/pm_domain.h > @@ -55,6 +55,10 @@ > * > * GENPD_FLAG_RPM_ALWAYS_ON: Instructs genpd to always keep the PM domain > * powered on except for system suspend. > + * > + * GENPD_FLAG_SUSPEND_ON: Instructs genpd to keep the PM domain powered > + * on during suspend and runtime PM controlled > + * otherwise. > */ > #define GENPD_FLAG_PM_CLK (1U << 0) > #define GENPD_FLAG_IRQ_SAFE (1U << 1) > @@ -62,6 +66,7 @@ > #define GENPD_FLAG_ACTIVE_WAKEUP (1U << 3) > #define GENPD_FLAG_CPU_DOMAIN (1U << 4) > #define GENPD_FLAG_RPM_ALWAYS_ON (1U << 5) > +#define GENPD_FLAG_SUSPEND_ON (1U << 6) > > enum gpd_status { > GPD_STATE_ACTIVE = 0, /* PM domain is active */ > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project >
Hey Stephen, Thanks for taking time to review the series! On 2020-08-12 03:08, Stephen Boyd wrote: > Quoting Sibi Sankar (2020-08-11 12:02:51) >> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h >> index ee11502a575b0..3002a2d68936a 100644 >> --- a/include/linux/pm_domain.h >> +++ b/include/linux/pm_domain.h >> @@ -55,6 +55,10 @@ >> * >> * GENPD_FLAG_RPM_ALWAYS_ON: Instructs genpd to always keep the PM >> domain >> * powered on except for system suspend. >> + * >> + * GENPD_FLAG_SUSPEND_ON: Instructs genpd to keep the PM domain >> powered >> + * on during suspend and runtime PM >> controlled > > Maybe, "powered on across system suspend (if it is already powered on)" > to match the hunk above that talks about system suspend for > GENPD_FLAG_RPM_ALWAYS_ON. Otherwise someone may think that this powers > on the genpd during suspend or powers it on during runtime suspend. Sure, I'll add ^^ in the next re-spin. > >> + * otherwise. >> */ >> #define GENPD_FLAG_PM_CLK (1U << 0) >> #define GENPD_FLAG_IRQ_SAFE (1U << 1)
Kevin, Thanks for taking time to review the series! On 2020-08-12 05:49, Kevin Hilman wrote: > Sibi Sankar <sibis@codeaurora.org> writes: > >> This is for power domains which needs to stay powered on for suspend >> but can be powered on/off as part of runtime PM. This flag is aimed at >> power domains coupled to remote processors which enter suspend states >> independent to that of the application processor. Such power domains >> are turned off only on remote processor crash/shutdown. >> >> Signed-off-by: Sibi Sankar <sibis@codeaurora.org> > > Seems like a useful use-case, but i think there should be a bit more > description/documentation about what is the expected/desired behavior > during system suspsend when a power-domain with this flag is already > runtime-PM suspended. Similarily, on system resume, what is the > expected/desired behavior? SUSPEND_ON flag is only aimed at keeping power domains powered on across suspend (only if its already powered on). Also if the power domain is runtime-PM suspended we wouldn't want to power it on during resume. diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 0a5afca250d03..547c091618008 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -1003,7 +1003,7 @@ static void genpd_sync_power_on(struct generic_pm_domain *genpd, bool use_lock, { struct gpd_link *link; - if (genpd_status_on(genpd)) + if (genpd_status_on(genpd) || genpd_is_suspend_on(genpd)) return; I'll add the ^^ diff in the next re-spin to prevent power on of a runtime-PM suspended power domain. > > Kevin
Uffe, Thanks for taking time to review the series! On 2020-08-12 15:15, Ulf Hansson wrote: > On Tue, 11 Aug 2020 at 21:03, Sibi Sankar <sibis@codeaurora.org> wrote: >> >> This is for power domains which needs to stay powered on for suspend >> but can be powered on/off as part of runtime PM. This flag is aimed at >> power domains coupled to remote processors which enter suspend states >> independent to that of the application processor. Such power domains >> are turned off only on remote processor crash/shutdown. > > As Kevin also requested, please elaborate more on the use case. > > Why exactly must the PM domain stay powered on during system suspend? > Is there a wakeup configured that needs to be managed - or is there a > co-processor/FW behaviour that needs to be obeyed to? Yes this is a co-processor behavior that needs to be obeyed. Specifically application processor notifies the Always on Subsystem (AOSS) that a particular co-processor is up using the power domains exposed by AOSS QMP driver. AOSS uses this information to wait for the co-processors to suspend before starting its sleep sequence. The application processor powers off these power domains only if the co-processor has crashed or powered off. > > Kind regards > Uffe > >> >> Signed-off-by: Sibi Sankar <sibis@codeaurora.org> >> --- >> drivers/base/power/domain.c | 3 ++- >> include/linux/pm_domain.h | 5 +++++ >> 2 files changed, 7 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c >> index 2cb5e04cf86cd..ba78ac4a450d4 100644 >> --- a/drivers/base/power/domain.c >> +++ b/drivers/base/power/domain.c >> @@ -129,6 +129,7 @@ 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_is_suspend_on(genpd) (genpd->flags & >> GENPD_FLAG_SUSPEND_ON) >> >> static inline bool irq_safe_dev_in_no_sleep_domain(struct device >> *dev, >> const struct generic_pm_domain *genpd) >> @@ -949,7 +950,7 @@ static void genpd_sync_power_off(struct >> generic_pm_domain *genpd, bool use_lock, >> { >> struct gpd_link *link; >> >> - if (!genpd_status_on(genpd) || genpd_is_always_on(genpd)) >> + if (!genpd_status_on(genpd) || genpd_is_always_on(genpd) || >> genpd_is_suspend_on(genpd)) >> return; >> >> if (genpd->suspended_count != genpd->device_count >> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h >> index ee11502a575b0..3002a2d68936a 100644 >> --- a/include/linux/pm_domain.h >> +++ b/include/linux/pm_domain.h >> @@ -55,6 +55,10 @@ >> * >> * GENPD_FLAG_RPM_ALWAYS_ON: Instructs genpd to always keep the PM >> domain >> * powered on except for system suspend. >> + * >> + * GENPD_FLAG_SUSPEND_ON: Instructs genpd to keep the PM domain >> powered >> + * on during suspend and runtime PM >> controlled >> + * otherwise. >> */ >> #define GENPD_FLAG_PM_CLK (1U << 0) >> #define GENPD_FLAG_IRQ_SAFE (1U << 1) >> @@ -62,6 +66,7 @@ >> #define GENPD_FLAG_ACTIVE_WAKEUP (1U << 3) >> #define GENPD_FLAG_CPU_DOMAIN (1U << 4) >> #define GENPD_FLAG_RPM_ALWAYS_ON (1U << 5) >> +#define GENPD_FLAG_SUSPEND_ON (1U << 6) >> >> enum gpd_status { >> GPD_STATE_ACTIVE = 0, /* PM domain is active */ >> -- >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora >> Forum, >> a Linux Foundation Collaborative Project >>
On Wed, 12 Aug 2020 at 19:03, Sibi Sankar <sibis@codeaurora.org> wrote: > > Uffe, > Thanks for taking time to review the > series! > > On 2020-08-12 15:15, Ulf Hansson wrote: > > On Tue, 11 Aug 2020 at 21:03, Sibi Sankar <sibis@codeaurora.org> wrote: > >> > >> This is for power domains which needs to stay powered on for suspend > >> but can be powered on/off as part of runtime PM. This flag is aimed at > >> power domains coupled to remote processors which enter suspend states > >> independent to that of the application processor. Such power domains > >> are turned off only on remote processor crash/shutdown. > > > > As Kevin also requested, please elaborate more on the use case. > > > > Why exactly must the PM domain stay powered on during system suspend? > > Is there a wakeup configured that needs to be managed - or is there a > > co-processor/FW behaviour that needs to be obeyed to? > > Yes this is a co-processor behavior that > needs to be obeyed. Specifically application > processor notifies the Always on Subsystem > (AOSS) that a particular co-processor is up > using the power domains exposed by AOSS QMP > driver. AOSS uses this information to wait > for the co-processors to suspend before > starting its sleep sequence. The application > processor powers off these power domains only > if the co-processor has crashed or powered > off. Thanks for clarifying! Although, can you please elaborate a bit more on the actual use case? What are the typical co-processor and what drivers are involved in managing it? As you may know, runtime PM becomes disabled during system suspend of a device. Which means, if the driver tries to power off the coprocessor (via calling pm_runtime_put() for example), somewhere in the system suspend phase of the corresponding device, its attached PM domain stays powered on when managed by genpd. Then in the suspend_noirq phase, genpd tries to power off the PM domain, unless there are wakeups to consider. Taking the above into account, wouldn't that mean that you potentially may end up keeping the PM domain powered on, even if it actually can be powered off in the suspend_noirq phase by genpd? Kind regards Uffe > > > >> > >> Signed-off-by: Sibi Sankar <sibis@codeaurora.org> > >> --- > >> drivers/base/power/domain.c | 3 ++- > >> include/linux/pm_domain.h | 5 +++++ > >> 2 files changed, 7 insertions(+), 1 deletion(-) > >> > >> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > >> index 2cb5e04cf86cd..ba78ac4a450d4 100644 > >> --- a/drivers/base/power/domain.c > >> +++ b/drivers/base/power/domain.c > >> @@ -129,6 +129,7 @@ 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_is_suspend_on(genpd) (genpd->flags & > >> GENPD_FLAG_SUSPEND_ON) > >> > >> static inline bool irq_safe_dev_in_no_sleep_domain(struct device > >> *dev, > >> const struct generic_pm_domain *genpd) > >> @@ -949,7 +950,7 @@ static void genpd_sync_power_off(struct > >> generic_pm_domain *genpd, bool use_lock, > >> { > >> struct gpd_link *link; > >> > >> - if (!genpd_status_on(genpd) || genpd_is_always_on(genpd)) > >> + if (!genpd_status_on(genpd) || genpd_is_always_on(genpd) || > >> genpd_is_suspend_on(genpd)) > >> return; > >> > >> if (genpd->suspended_count != genpd->device_count > >> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h > >> index ee11502a575b0..3002a2d68936a 100644 > >> --- a/include/linux/pm_domain.h > >> +++ b/include/linux/pm_domain.h > >> @@ -55,6 +55,10 @@ > >> * > >> * GENPD_FLAG_RPM_ALWAYS_ON: Instructs genpd to always keep the PM > >> domain > >> * powered on except for system suspend. > >> + * > >> + * GENPD_FLAG_SUSPEND_ON: Instructs genpd to keep the PM domain > >> powered > >> + * on during suspend and runtime PM > >> controlled > >> + * otherwise. > >> */ > >> #define GENPD_FLAG_PM_CLK (1U << 0) > >> #define GENPD_FLAG_IRQ_SAFE (1U << 1) > >> @@ -62,6 +66,7 @@ > >> #define GENPD_FLAG_ACTIVE_WAKEUP (1U << 3) > >> #define GENPD_FLAG_CPU_DOMAIN (1U << 4) > >> #define GENPD_FLAG_RPM_ALWAYS_ON (1U << 5) > >> +#define GENPD_FLAG_SUSPEND_ON (1U << 6) > >> > >> enum gpd_status { > >> GPD_STATE_ACTIVE = 0, /* PM domain is active */ > >> -- > >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora > >> Forum, > >> a Linux Foundation Collaborative Project > >> > > -- > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, > a Linux Foundation Collaborative Project.
On 2020-08-13 18:04, Ulf Hansson wrote: > On Wed, 12 Aug 2020 at 19:03, Sibi Sankar <sibis@codeaurora.org> wrote: >> >> Uffe, >> Thanks for taking time to review the >> series! >> >> On 2020-08-12 15:15, Ulf Hansson wrote: >> > On Tue, 11 Aug 2020 at 21:03, Sibi Sankar <sibis@codeaurora.org> wrote: >> >> >> >> This is for power domains which needs to stay powered on for suspend >> >> but can be powered on/off as part of runtime PM. This flag is aimed at >> >> power domains coupled to remote processors which enter suspend states >> >> independent to that of the application processor. Such power domains >> >> are turned off only on remote processor crash/shutdown. >> > >> > As Kevin also requested, please elaborate more on the use case. >> > >> > Why exactly must the PM domain stay powered on during system suspend? >> > Is there a wakeup configured that needs to be managed - or is there a >> > co-processor/FW behaviour that needs to be obeyed to? >> >> Yes this is a co-processor behavior that >> needs to be obeyed. Specifically application >> processor notifies the Always on Subsystem >> (AOSS) that a particular co-processor is up >> using the power domains exposed by AOSS QMP >> driver. AOSS uses this information to wait >> for the co-processors to suspend before >> starting its sleep sequence. The application >> processor powers off these power domains only >> if the co-processor has crashed or powered >> off. > > Thanks for clarifying! > > Although, can you please elaborate a bit more on the actual use case? > What are the typical co-processor and what drivers are involved in > managing it? The co-processors using the power domains exposed by qcom_aoss driver are modem, audio dsp, compute dsp managed using qcom_q6v5_mss and qcom_q6v5_pas driver. > > As you may know, runtime PM becomes disabled during system suspend of > a device. Which means, if the driver tries to power off the > coprocessor (via calling pm_runtime_put() for example), somewhere in > the system suspend phase of the corresponding device, its attached PM > domain stays powered on when managed by genpd. The drivers aren't really expected do anything during suspend/resume pretty much because the co-processors enter low-power modes independent to that of the application processor. On co-processor crash the remoteproc core does a pm_stay_awake followed by a pm_relax after crash recovery. > > Then in the suspend_noirq phase, genpd tries to power off the PM > domain, unless there are wakeups to consider. > > Taking the above into account, wouldn't that mean that you potentially > may end up keeping the PM domain powered on, even if it actually can > be powered off in the suspend_noirq phase by genpd? > > Kind regards > Uffe > >> > >> >> >> >> Signed-off-by: Sibi Sankar <sibis@codeaurora.org> >> >> --- >> >> drivers/base/power/domain.c | 3 ++- >> >> include/linux/pm_domain.h | 5 +++++ >> >> 2 files changed, 7 insertions(+), 1 deletion(-) >> >> >> >> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c >> >> index 2cb5e04cf86cd..ba78ac4a450d4 100644 >> >> --- a/drivers/base/power/domain.c >> >> +++ b/drivers/base/power/domain.c >> >> @@ -129,6 +129,7 @@ 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_is_suspend_on(genpd) (genpd->flags & >> >> GENPD_FLAG_SUSPEND_ON) >> >> >> >> static inline bool irq_safe_dev_in_no_sleep_domain(struct device >> >> *dev, >> >> const struct generic_pm_domain *genpd) >> >> @@ -949,7 +950,7 @@ static void genpd_sync_power_off(struct >> >> generic_pm_domain *genpd, bool use_lock, >> >> { >> >> struct gpd_link *link; >> >> >> >> - if (!genpd_status_on(genpd) || genpd_is_always_on(genpd)) >> >> + if (!genpd_status_on(genpd) || genpd_is_always_on(genpd) || >> >> genpd_is_suspend_on(genpd)) >> >> return; >> >> >> >> if (genpd->suspended_count != genpd->device_count >> >> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h >> >> index ee11502a575b0..3002a2d68936a 100644 >> >> --- a/include/linux/pm_domain.h >> >> +++ b/include/linux/pm_domain.h >> >> @@ -55,6 +55,10 @@ >> >> * >> >> * GENPD_FLAG_RPM_ALWAYS_ON: Instructs genpd to always keep the PM >> >> domain >> >> * powered on except for system suspend. >> >> + * >> >> + * GENPD_FLAG_SUSPEND_ON: Instructs genpd to keep the PM domain >> >> powered >> >> + * on during suspend and runtime PM >> >> controlled >> >> + * otherwise. >> >> */ >> >> #define GENPD_FLAG_PM_CLK (1U << 0) >> >> #define GENPD_FLAG_IRQ_SAFE (1U << 1) >> >> @@ -62,6 +66,7 @@ >> >> #define GENPD_FLAG_ACTIVE_WAKEUP (1U << 3) >> >> #define GENPD_FLAG_CPU_DOMAIN (1U << 4) >> >> #define GENPD_FLAG_RPM_ALWAYS_ON (1U << 5) >> >> +#define GENPD_FLAG_SUSPEND_ON (1U << 6) >> >> >> >> enum gpd_status { >> >> GPD_STATE_ACTIVE = 0, /* PM domain is active */ >> >> -- >> >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora >> >> Forum, >> >> a Linux Foundation Collaborative Project >> >> >> >> -- >> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, >> a Linux Foundation Collaborative Project.
On Thu, 13 Aug 2020 at 19:26, Sibi Sankar <sibis@codeaurora.org> wrote: > > On 2020-08-13 18:04, Ulf Hansson wrote: > > On Wed, 12 Aug 2020 at 19:03, Sibi Sankar <sibis@codeaurora.org> wrote: > >> > >> Uffe, > >> Thanks for taking time to review the > >> series! > >> > >> On 2020-08-12 15:15, Ulf Hansson wrote: > >> > On Tue, 11 Aug 2020 at 21:03, Sibi Sankar <sibis@codeaurora.org> wrote: > >> >> > >> >> This is for power domains which needs to stay powered on for suspend > >> >> but can be powered on/off as part of runtime PM. This flag is aimed at > >> >> power domains coupled to remote processors which enter suspend states > >> >> independent to that of the application processor. Such power domains > >> >> are turned off only on remote processor crash/shutdown. > >> > > >> > As Kevin also requested, please elaborate more on the use case. > >> > > >> > Why exactly must the PM domain stay powered on during system suspend? > >> > Is there a wakeup configured that needs to be managed - or is there a > >> > co-processor/FW behaviour that needs to be obeyed to? > >> > >> Yes this is a co-processor behavior that > >> needs to be obeyed. Specifically application > >> processor notifies the Always on Subsystem > >> (AOSS) that a particular co-processor is up > >> using the power domains exposed by AOSS QMP > >> driver. AOSS uses this information to wait > >> for the co-processors to suspend before > >> starting its sleep sequence. The application > >> processor powers off these power domains only > >> if the co-processor has crashed or powered > >> off. > > > > Thanks for clarifying! > > > > Although, can you please elaborate a bit more on the actual use case? > > What are the typical co-processor and what drivers are involved in > > managing it? > > The co-processors using the power domains > exposed by qcom_aoss driver are modem, > audio dsp, compute dsp managed using > qcom_q6v5_mss and qcom_q6v5_pas driver. > > > > > As you may know, runtime PM becomes disabled during system suspend of > > a device. Which means, if the driver tries to power off the > > coprocessor (via calling pm_runtime_put() for example), somewhere in > > the system suspend phase of the corresponding device, its attached PM > > domain stays powered on when managed by genpd. > > The drivers aren't really expected > do anything during suspend/resume > pretty much because the co-processors > enter low-power modes independent to > that of the application processor. On > co-processor crash the remoteproc core > does a pm_stay_awake followed by a > pm_relax after crash recovery. Okay, thanks again for clarifying. You have convinced me about the need for a new flag to cope with these use cases. Would you mind updating the commit message with some of the information you just provided? Additionally, to make it clear that the flag should be used to keep the PM domain powered on during system suspend, but only if it's already powered on - please rename the flag to GENPD_FLAG_NO_SUSPEND, and update the corresponding description of it in the header file. [...] Kind regards Uffe
On 2020-08-17 14:14, Ulf Hansson wrote: > On Thu, 13 Aug 2020 at 19:26, Sibi Sankar <sibis@codeaurora.org> wrote: >> >> On 2020-08-13 18:04, Ulf Hansson wrote: >> > On Wed, 12 Aug 2020 at 19:03, Sibi Sankar <sibis@codeaurora.org> wrote: >> >> >> >> Uffe, >> >> Thanks for taking time to review the >> >> series! >> >> >> >> On 2020-08-12 15:15, Ulf Hansson wrote: >> >> > On Tue, 11 Aug 2020 at 21:03, Sibi Sankar <sibis@codeaurora.org> wrote: >> >> >> >> >> >> This is for power domains which needs to stay powered on for suspend >> >> >> but can be powered on/off as part of runtime PM. This flag is aimed at >> >> >> power domains coupled to remote processors which enter suspend states >> >> >> independent to that of the application processor. Such power domains >> >> >> are turned off only on remote processor crash/shutdown. >> >> > >> >> > As Kevin also requested, please elaborate more on the use case. >> >> > >> >> > Why exactly must the PM domain stay powered on during system suspend? >> >> > Is there a wakeup configured that needs to be managed - or is there a >> >> > co-processor/FW behaviour that needs to be obeyed to? >> >> >> >> Yes this is a co-processor behavior that >> >> needs to be obeyed. Specifically application >> >> processor notifies the Always on Subsystem >> >> (AOSS) that a particular co-processor is up >> >> using the power domains exposed by AOSS QMP >> >> driver. AOSS uses this information to wait >> >> for the co-processors to suspend before >> >> starting its sleep sequence. The application >> >> processor powers off these power domains only >> >> if the co-processor has crashed or powered >> >> off. >> > >> > Thanks for clarifying! >> > >> > Although, can you please elaborate a bit more on the actual use case? >> > What are the typical co-processor and what drivers are involved in >> > managing it? >> >> The co-processors using the power domains >> exposed by qcom_aoss driver are modem, >> audio dsp, compute dsp managed using >> qcom_q6v5_mss and qcom_q6v5_pas driver. >> >> > >> > As you may know, runtime PM becomes disabled during system suspend of >> > a device. Which means, if the driver tries to power off the >> > coprocessor (via calling pm_runtime_put() for example), somewhere in >> > the system suspend phase of the corresponding device, its attached PM >> > domain stays powered on when managed by genpd. >> >> The drivers aren't really expected >> do anything during suspend/resume >> pretty much because the co-processors >> enter low-power modes independent to >> that of the application processor. On >> co-processor crash the remoteproc core >> does a pm_stay_awake followed by a >> pm_relax after crash recovery. > > Okay, thanks again for clarifying. You have convinced me about the > need for a new flag to cope with these use cases. > > Would you mind updating the commit message with some of the > information you just provided? > > Additionally, to make it clear that the flag should be used to keep > the PM domain powered on during system suspend, but only if it's > already powered on - please rename the flag to GENPD_FLAG_NO_SUSPEND, > and update the corresponding description of it in the header file. Thanks, naming it ^^ makes more sense :) https://lore.kernel.org/lkml/340a7aafcf0301ff3158a4e211992041@codeaurora.org/ Also we wouldn't want to power on runtime suspended power domains with the NO_SUSPEND flag set, on resume as explained ^^. Do you agree with that as well? > > [...] > > Kind regards > Uffe
On Mon, 17 Aug 2020 at 18:49, Sibi Sankar <sibis@codeaurora.org> wrote: > > On 2020-08-17 14:14, Ulf Hansson wrote: > > On Thu, 13 Aug 2020 at 19:26, Sibi Sankar <sibis@codeaurora.org> wrote: > >> > >> On 2020-08-13 18:04, Ulf Hansson wrote: > >> > On Wed, 12 Aug 2020 at 19:03, Sibi Sankar <sibis@codeaurora.org> wrote: > >> >> > >> >> Uffe, > >> >> Thanks for taking time to review the > >> >> series! > >> >> > >> >> On 2020-08-12 15:15, Ulf Hansson wrote: > >> >> > On Tue, 11 Aug 2020 at 21:03, Sibi Sankar <sibis@codeaurora.org> wrote: > >> >> >> > >> >> >> This is for power domains which needs to stay powered on for suspend > >> >> >> but can be powered on/off as part of runtime PM. This flag is aimed at > >> >> >> power domains coupled to remote processors which enter suspend states > >> >> >> independent to that of the application processor. Such power domains > >> >> >> are turned off only on remote processor crash/shutdown. > >> >> > > >> >> > As Kevin also requested, please elaborate more on the use case. > >> >> > > >> >> > Why exactly must the PM domain stay powered on during system suspend? > >> >> > Is there a wakeup configured that needs to be managed - or is there a > >> >> > co-processor/FW behaviour that needs to be obeyed to? > >> >> > >> >> Yes this is a co-processor behavior that > >> >> needs to be obeyed. Specifically application > >> >> processor notifies the Always on Subsystem > >> >> (AOSS) that a particular co-processor is up > >> >> using the power domains exposed by AOSS QMP > >> >> driver. AOSS uses this information to wait > >> >> for the co-processors to suspend before > >> >> starting its sleep sequence. The application > >> >> processor powers off these power domains only > >> >> if the co-processor has crashed or powered > >> >> off. > >> > > >> > Thanks for clarifying! > >> > > >> > Although, can you please elaborate a bit more on the actual use case? > >> > What are the typical co-processor and what drivers are involved in > >> > managing it? > >> > >> The co-processors using the power domains > >> exposed by qcom_aoss driver are modem, > >> audio dsp, compute dsp managed using > >> qcom_q6v5_mss and qcom_q6v5_pas driver. > >> > >> > > >> > As you may know, runtime PM becomes disabled during system suspend of > >> > a device. Which means, if the driver tries to power off the > >> > coprocessor (via calling pm_runtime_put() for example), somewhere in > >> > the system suspend phase of the corresponding device, its attached PM > >> > domain stays powered on when managed by genpd. > >> > >> The drivers aren't really expected > >> do anything during suspend/resume > >> pretty much because the co-processors > >> enter low-power modes independent to > >> that of the application processor. On > >> co-processor crash the remoteproc core > >> does a pm_stay_awake followed by a > >> pm_relax after crash recovery. > > > > Okay, thanks again for clarifying. You have convinced me about the > > need for a new flag to cope with these use cases. > > > > Would you mind updating the commit message with some of the > > information you just provided? > > > > Additionally, to make it clear that the flag should be used to keep > > the PM domain powered on during system suspend, but only if it's > > already powered on - please rename the flag to GENPD_FLAG_NO_SUSPEND, > > and update the corresponding description of it in the header file. > > Thanks, naming it ^^ makes more sense :) > > https://lore.kernel.org/lkml/340a7aafcf0301ff3158a4e211992041@codeaurora.org/ > > Also we wouldn't want to power on > runtime suspended power domains with > the NO_SUSPEND flag set, on resume as > explained ^^. Do you agree with that > as well? Actually no. Instead, I think that deserves a separate flag, as it may very well turn out that resuming can be skipped for other cases than "NO_SUSPEND". Therefore, please add a GENPD_FLAG_NO_RESUME for this. Kind regards Uffe
On 2020-08-18 14:01, Ulf Hansson wrote: > On Mon, 17 Aug 2020 at 18:49, Sibi Sankar <sibis@codeaurora.org> wrote: >> >> On 2020-08-17 14:14, Ulf Hansson wrote: >> > On Thu, 13 Aug 2020 at 19:26, Sibi Sankar <sibis@codeaurora.org> wrote: >> >> >> >> On 2020-08-13 18:04, Ulf Hansson wrote: >> >> > On Wed, 12 Aug 2020 at 19:03, Sibi Sankar <sibis@codeaurora.org> wrote: >> >> >> >> >> >> Uffe, >> >> >> Thanks for taking time to review the >> >> >> series! >> >> >> >> >> >> On 2020-08-12 15:15, Ulf Hansson wrote: >> >> >> > On Tue, 11 Aug 2020 at 21:03, Sibi Sankar <sibis@codeaurora.org> wrote: >> >> >> >> >> >> >> >> This is for power domains which needs to stay powered on for suspend >> >> >> >> but can be powered on/off as part of runtime PM. This flag is aimed at >> >> >> >> power domains coupled to remote processors which enter suspend states >> >> >> >> independent to that of the application processor. Such power domains >> >> >> >> are turned off only on remote processor crash/shutdown. >> >> >> > >> >> >> > As Kevin also requested, please elaborate more on the use case. >> >> >> > >> >> >> > Why exactly must the PM domain stay powered on during system suspend? >> >> >> > Is there a wakeup configured that needs to be managed - or is there a >> >> >> > co-processor/FW behaviour that needs to be obeyed to? >> >> >> >> >> >> Yes this is a co-processor behavior that >> >> >> needs to be obeyed. Specifically application >> >> >> processor notifies the Always on Subsystem >> >> >> (AOSS) that a particular co-processor is up >> >> >> using the power domains exposed by AOSS QMP >> >> >> driver. AOSS uses this information to wait >> >> >> for the co-processors to suspend before >> >> >> starting its sleep sequence. The application >> >> >> processor powers off these power domains only >> >> >> if the co-processor has crashed or powered >> >> >> off. >> >> > >> >> > Thanks for clarifying! >> >> > >> >> > Although, can you please elaborate a bit more on the actual use case? >> >> > What are the typical co-processor and what drivers are involved in >> >> > managing it? >> >> >> >> The co-processors using the power domains >> >> exposed by qcom_aoss driver are modem, >> >> audio dsp, compute dsp managed using >> >> qcom_q6v5_mss and qcom_q6v5_pas driver. >> >> >> >> > >> >> > As you may know, runtime PM becomes disabled during system suspend of >> >> > a device. Which means, if the driver tries to power off the >> >> > coprocessor (via calling pm_runtime_put() for example), somewhere in >> >> > the system suspend phase of the corresponding device, its attached PM >> >> > domain stays powered on when managed by genpd. >> >> >> >> The drivers aren't really expected >> >> do anything during suspend/resume >> >> pretty much because the co-processors >> >> enter low-power modes independent to >> >> that of the application processor. On >> >> co-processor crash the remoteproc core >> >> does a pm_stay_awake followed by a >> >> pm_relax after crash recovery. >> > >> > Okay, thanks again for clarifying. You have convinced me about the >> > need for a new flag to cope with these use cases. >> > >> > Would you mind updating the commit message with some of the >> > information you just provided? >> > >> > Additionally, to make it clear that the flag should be used to keep >> > the PM domain powered on during system suspend, but only if it's >> > already powered on - please rename the flag to GENPD_FLAG_NO_SUSPEND, >> > and update the corresponding description of it in the header file. >> >> Thanks, naming it ^^ makes more sense :) >> >> https://lore.kernel.org/lkml/340a7aafcf0301ff3158a4e211992041@codeaurora.org/ >> >> Also we wouldn't want to power on >> runtime suspended power domains with >> the NO_SUSPEND flag set, on resume as >> explained ^^. Do you agree with that >> as well? > > Actually no. > > Instead, I think that deserves a separate flag, as it may very well > turn out that resuming can be skipped for other cases than > "NO_SUSPEND". > > Therefore, please add a GENPD_FLAG_NO_RESUME for this. Thanks I'll do that in v2 > > Kind regards > Uffe
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 2cb5e04cf86cd..ba78ac4a450d4 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -129,6 +129,7 @@ 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_is_suspend_on(genpd) (genpd->flags & GENPD_FLAG_SUSPEND_ON) static inline bool irq_safe_dev_in_no_sleep_domain(struct device *dev, const struct generic_pm_domain *genpd) @@ -949,7 +950,7 @@ static void genpd_sync_power_off(struct generic_pm_domain *genpd, bool use_lock, { struct gpd_link *link; - if (!genpd_status_on(genpd) || genpd_is_always_on(genpd)) + if (!genpd_status_on(genpd) || genpd_is_always_on(genpd) || genpd_is_suspend_on(genpd)) return; if (genpd->suspended_count != genpd->device_count diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index ee11502a575b0..3002a2d68936a 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -55,6 +55,10 @@ * * GENPD_FLAG_RPM_ALWAYS_ON: Instructs genpd to always keep the PM domain * powered on except for system suspend. + * + * GENPD_FLAG_SUSPEND_ON: Instructs genpd to keep the PM domain powered + * on during suspend and runtime PM controlled + * otherwise. */ #define GENPD_FLAG_PM_CLK (1U << 0) #define GENPD_FLAG_IRQ_SAFE (1U << 1) @@ -62,6 +66,7 @@ #define GENPD_FLAG_ACTIVE_WAKEUP (1U << 3) #define GENPD_FLAG_CPU_DOMAIN (1U << 4) #define GENPD_FLAG_RPM_ALWAYS_ON (1U << 5) +#define GENPD_FLAG_SUSPEND_ON (1U << 6) enum gpd_status { GPD_STATE_ACTIVE = 0, /* PM domain is active */
This is for power domains which needs to stay powered on for suspend but can be powered on/off as part of runtime PM. This flag is aimed at power domains coupled to remote processors which enter suspend states independent to that of the application processor. Such power domains are turned off only on remote processor crash/shutdown. Signed-off-by: Sibi Sankar <sibis@codeaurora.org> --- drivers/base/power/domain.c | 3 ++- include/linux/pm_domain.h | 5 +++++ 2 files changed, 7 insertions(+), 1 deletion(-)