On Tue, Dec 22 2020 at 03:16 -0700, Ulf Hansson wrote:
On Wed, 16 Dec 2020 at 18:51, Lina Iyer <ilina@xxxxxxxxxxxxxx> wrote:
In order to debug critical domain and device power issues, it may be
necessary to disallow certain idle states at runtime. Let the device
disallow a domain idle state before suspending.The domain governor shall
check for the 'disabled' flag while determining the domain idle state.
For debug purposes, you might as well just set a dev PM Qos latency
request that corresponds to the state you want to disable. This will
then prevent the genpd governor from selecting the state.
True, but it will also disable idle states deeper as well. Would like to
avoid that.
--Lina
Kind regards
Uffe
Signed-off-by: Lina Iyer <ilina@xxxxxxxxxxxxxx>
---
drivers/base/power/domain.c | 30 ++++++++++++++++++++++++++++
drivers/base/power/domain_governor.c | 3 +++
include/linux/pm_domain.h | 7 +++++++
3 files changed, 40 insertions(+)
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 191539a8e06d..e4e7ab75bdea 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1926,6 +1926,36 @@ int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
}
EXPORT_SYMBOL_GPL(pm_genpd_remove_subdomain);
+/**
+ * dev_pm_genpd_disable_idle_state - Disallow a PM domain's idle state
+ *
+ * @dev: device attached to the PM domain
+ * @idx: index of the PM domain's idle state to be disabled
+ * @disable: enable/disable idle state
+ *
+ * Allow a PM domain's idle state to be disabled. Disabled idle states will
+ * be ignored by the domain governor when entering idle. Devices would
+ * invoke this before calling runtime suspend.
+ */
+int dev_pm_genpd_disable_idle_state(struct device *dev, unsigned int idx, bool disable)
+{
+ struct generic_pm_domain *genpd;
+
+ genpd = dev_to_genpd_safe(dev);
+ if (!genpd)
+ return -ENODEV;
+
+ if (idx >= genpd->state_count)
+ return -EINVAL;
+
+ genpd_lock(genpd);
+ genpd->states[idx].disabled = disable;
+ genpd_unlock(genpd);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dev_pm_genpd_disable_idle_state);
+
static void genpd_free_default_power_state(struct genpd_power_state *states,
unsigned int state_count)
{
diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c
index 2afb7fa90d5d..8decd17c5a6a 100644
--- a/drivers/base/power/domain_governor.c
+++ b/drivers/base/power/domain_governor.c
@@ -175,6 +175,9 @@ static bool __default_power_down_ok(struct dev_pm_domain *pd,
s64 min_off_time_ns;
s64 off_on_time_ns;
+ if (genpd->states[state].disabled)
+ return false;
+
off_on_time_ns = genpd->states[state].power_off_latency_ns +
genpd->states[state].power_on_latency_ns;
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index a41aea9d1c06..3d251b5b461a 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -101,6 +101,7 @@ struct genpd_power_state {
struct fwnode_handle *fwnode;
ktime_t idle_time;
void *data;
+ bool disabled;
};
struct genpd_lock_ops;
@@ -233,6 +234,7 @@ int dev_pm_genpd_add_notifier(struct device *dev, struct notifier_block *nb);
int dev_pm_genpd_remove_notifier(struct device *dev);
void genpd_enable_next_wakeup(struct generic_pm_domain *genpd, bool enable);
int dev_pm_genpd_set_next_wakeup(struct device *dev, ktime_t next);
+int dev_pm_genpd_disable_idle_state(struct device *dev, unsigned int idx, bool disable);
extern struct dev_power_governor simple_qos_governor;
extern struct dev_power_governor pm_domain_always_on_gov;
@@ -300,6 +302,11 @@ static inline int dev_pm_genpd_set_next_wakeup(struct device *dev, ktime_t next)
return -EOPNOTSUPP;
}
+static inline int dev_pm_genpd_disable_idle_state(struct device *dev, unsigned int idx, bool disable)
+{
+ return -EOPNOTSUPP;
+}
+
#define simple_qos_governor (*(struct dev_power_governor *)(NULL))
#define pm_domain_always_on_gov (*(struct dev_power_governor *)(NULL))
#endif
--
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