[PATCH v5 0/2] Small runtime PM API changes

[PATCH v5 0/2] Small runtime PM API changes

[Sakari Ailus]

Hi folks,

Here's a small but a different set of patches for making two relatively
minor changes to runtime PM API. I restarted version numbering as this is
meaningfully different from the previous set.

pm_runtime_get_if_active() loses its second argument as it only made sense
to have ign_usage_count argument true.

The other change is also small but it has an effect on callers:
pm_runtime_put_autosuspend() will, in the future, be re-purposed to
include a call to pm_runtime_mark_last_busy() as well. Before this,
current users of the function are moved to __pm_runtime_put_autosuspend()
(added by this patchset) which will continue to have the current
behaviour.

I haven't included the conversion patches in this set as I only want to do
that once this set has been approved and merged. The tree specific patches
can be found here, on linux-next master (there are some V4L2 patches
there, too, please ignore them for now):
<URL:https://git.kernel.org/pub/scm/linux/kernel/git/sailus/linux-next.git/log/?

Later on, users calling pm_runtime_mark_last_busy() immediately followed
by __pm_runtime_put_autosuspend() will be switched back to
pm_runtime_put_autosuspend() once its behaviour change has been done (a
patch near top of that branch). I'll provide these once the preceding ones
have been merged.

Comments are welcome.

since v4:

- patch 1: Squash patch 2
  <URL:https://lists.freedesktop.org/archives/dri-devel/2024-January/438739.html>.

- patch 1: Add to documentation of pm_runtime_get_if_{active,in_use} that
  if PM runtime is disabled, an error is returned and the usage_count
  remains unmodified.

- patch 1: Fix spelling of "explicitly" in the commit message.

- Use upper case "PM:" prefix in subject.

since v3:

- patch 1: Drop the previously added documentation on driver use of
  pm_runtime_get_conditional().

- Add a patch to make pm_runtime_get_conditional() static, including
  switching i915 to pm_runtime_get_if_{active,in_use}.

since v2:

- Rebase on v6.8-rc1 (no changes).

- Add Rodrigo's Reviewed-by: to the 1st patch.

since v1:

- patch 1: Rename __pm_runtime_get_conditional() as
  pm_runtime_get_conditional().

- patch 1: Reword documentation on driver use of
  pm_runtime_get_conditional().

Sakari Ailus (2):
  PM: runtime: Simplify pm_runtime_get_if_active() usage
  PM: runtime: Add pm_runtime_put_autosuspend() replacement

 Documentation/power/runtime_pm.rst      | 22 +++++++++-------
 drivers/accel/ivpu/ivpu_pm.c            |  2 +-
 drivers/base/power/runtime.c            | 35 +++++++++++++++++++++++--
 drivers/gpu/drm/i915/intel_runtime_pm.c |  5 +++-
 drivers/gpu/drm/xe/xe_pm.c              |  2 +-
 drivers/media/i2c/ccs/ccs-core.c        |  2 +-
 drivers/media/i2c/ov64a40.c             |  2 +-
 drivers/media/i2c/thp7312.c             |  2 +-
 drivers/net/ipa/ipa_smp2p.c             |  2 +-
 drivers/pci/pci.c                       |  2 +-
 include/linux/pm_runtime.h              | 30 ++++++++++-----------
 sound/hda/hdac_device.c                 |  2 +-
 12 files changed, 73 insertions(+), 35 deletions(-)

-- 
2.39.2

[PATCH v5 1/2] PM: runtime: Simplify pm_runtime_get_if_active() usage

[Sakari Ailus]

There are two ways to opportunistically increment a device's runtime PM
usage count, calling either pm_runtime_get_if_active() or
pm_runtime_get_if_in_use(). The former has an argument to tell whether to
ignore the usage count or not, and the latter simply calls the former with
ign_usage_count set to false. The other users that want to ignore the
usage_count will have to explicitly set that argument to true which is a
bit cumbersome.

To make this function more practical to use, remove the ign_usage_count
argument from the function. The main implementation is in a static
function called pm_runtime_get_conditional() and implementations of
pm_runtime_get_if_active() and pm_runtime_get_if_in_use() are moved to
runtime.c.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Takashi Iwai <tiwai@suse.de> # sound/
Reviewed-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com> # drivers/accel/ivpu/
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com> # drivers/gpu/drm/i915/
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> # drivers/pci/
---
 Documentation/power/runtime_pm.rst      |  5 ++--
 drivers/accel/ivpu/ivpu_pm.c            |  2 +-
 drivers/base/power/runtime.c            | 35 +++++++++++++++++++++++--
 drivers/gpu/drm/i915/intel_runtime_pm.c |  5 +++-
 drivers/gpu/drm/xe/xe_pm.c              |  2 +-
 drivers/media/i2c/ccs/ccs-core.c        |  2 +-
 drivers/media/i2c/ov64a40.c             |  2 +-
 drivers/media/i2c/thp7312.c             |  2 +-
 drivers/net/ipa/ipa_smp2p.c             |  2 +-
 drivers/pci/pci.c                       |  2 +-
 include/linux/pm_runtime.h              | 18 +++----------
 sound/hda/hdac_device.c                 |  2 +-
 12 files changed, 50 insertions(+), 29 deletions(-)

diff --git a/Documentation/power/runtime_pm.rst b/Documentation/power/runtime_pm.rst
index 65b86e487afe..da99379071a4 100644
--- a/Documentation/power/runtime_pm.rst
+++ b/Documentation/power/runtime_pm.rst
@@ -396,10 +396,9 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
       nonzero, increment the counter and return 1; otherwise return 0 without
       changing the counter
 
-  `int pm_runtime_get_if_active(struct device *dev, bool ign_usage_count);`
+  `int pm_runtime_get_if_active(struct device *dev);`
     - return -EINVAL if 'power.disable_depth' is nonzero; otherwise, if the
-      runtime PM status is RPM_ACTIVE, and either ign_usage_count is true
-      or the device's usage_count is non-zero, increment the counter and
+      runtime PM status is RPM_ACTIVE, increment the counter and
       return 1; otherwise return 0 without changing the counter
 
   `void pm_runtime_put_noidle(struct device *dev);`
diff --git a/drivers/accel/ivpu/ivpu_pm.c b/drivers/accel/ivpu/ivpu_pm.c
index 0af8864cb3b5..c6d93c7a1c58 100644
--- a/drivers/accel/ivpu/ivpu_pm.c
+++ b/drivers/accel/ivpu/ivpu_pm.c
@@ -292,7 +292,7 @@ int ivpu_rpm_get_if_active(struct ivpu_device *vdev)
 {
 	int ret;
 
-	ret = pm_runtime_get_if_active(vdev->drm.dev, false);
+	ret = pm_runtime_get_if_in_use(vdev->drm.dev);
 	drm_WARN_ON(&vdev->drm, ret < 0);
 
 	return ret;
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 05793c9fbb84..5275a6b2e980 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1176,7 +1176,7 @@ int __pm_runtime_resume(struct device *dev, int rpmflags)
 EXPORT_SYMBOL_GPL(__pm_runtime_resume);
 
 /**
- * pm_runtime_get_if_active - Conditionally bump up device usage counter.
+ * pm_runtime_get_conditional - Conditionally bump up device usage counter.
  * @dev: Device to handle.
  * @ign_usage_count: Whether or not to look at the current usage counter value.
  *
@@ -1197,7 +1197,7 @@ EXPORT_SYMBOL_GPL(__pm_runtime_resume);
  * The caller is responsible for decrementing the runtime PM usage counter of
  * @dev after this function has returned a positive value for it.
  */
-int pm_runtime_get_if_active(struct device *dev, bool ign_usage_count)
+static int pm_runtime_get_conditional(struct device *dev, bool ign_usage_count)
 {
 	unsigned long flags;
 	int retval;
@@ -1218,8 +1218,39 @@ int pm_runtime_get_if_active(struct device *dev, bool ign_usage_count)
 
 	return retval;
 }
+
+/**
+ * pm_runtime_get_if_active - Bump up runtime PM usage counter if the device is
+ *			      in active state
+ * @dev: Target device.
+ *
+ * Increment the runtime PM usage counter of @dev if its runtime PM status is
+ * %RPM_ACTIVE, in which case it returns 1. If the device is in a different
+ * state, 0 is returned. -EINVAL is returned if runtime PM is disabled for the
+ * device, in which case also the usage_count will remain unmodified.
+ */
+int pm_runtime_get_if_active(struct device *dev)
+{
+	return pm_runtime_get_conditional(dev, true);
+}
 EXPORT_SYMBOL_GPL(pm_runtime_get_if_active);
 
+/**
+ * pm_runtime_get_if_in_use - Conditionally bump up runtime PM usage counter.
+ * @dev: Target device.
+ *
+ * Increment the runtime PM usage counter of @dev if its runtime PM status is
+ * %RPM_ACTIVE and its runtime PM usage counter is greater than 0, in which case
+ * it returns 1. If the device is in a different state or its usage_count is 0,
+ * 0 is returned. -EINVAL is returned if runtime PM is disabled for the device,
+ * in which case also the usage_count will remain unmodified.
+ */
+int pm_runtime_get_if_in_use(struct device *dev)
+{
+	return pm_runtime_get_conditional(dev, false);
+}
+EXPORT_SYMBOL_GPL(pm_runtime_get_if_in_use);
+
 /**
  * __pm_runtime_set_status - Set runtime PM status of a device.
  * @dev: Device to handle.
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 860b51b56a92..d4e844128826 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -246,7 +246,10 @@ static intel_wakeref_t __intel_runtime_pm_get_if_active(struct intel_runtime_pm
 		 * function, since the power state is undefined. This applies
 		 * atm to the late/early system suspend/resume handlers.
 		 */
-		if (pm_runtime_get_if_active(rpm->kdev, ignore_usecount) <= 0)
+		if ((ignore_usecount &&
+		     pm_runtime_get_if_active(rpm->kdev) <= 0) ||
+		    (!ignore_usecount &&
+		     pm_runtime_get_if_in_use(rpm->kdev) <= 0))
 			return 0;
 	}
 
diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
index b429c2876a76..dd110058bf74 100644
--- a/drivers/gpu/drm/xe/xe_pm.c
+++ b/drivers/gpu/drm/xe/xe_pm.c
@@ -330,7 +330,7 @@ int xe_pm_runtime_put(struct xe_device *xe)
 
 int xe_pm_runtime_get_if_active(struct xe_device *xe)
 {
-	return pm_runtime_get_if_active(xe->drm.dev, true);
+	return pm_runtime_get_if_active(xe->drm.dev);
 }
 
 void xe_pm_assert_unbounded_bridge(struct xe_device *xe)
diff --git a/drivers/media/i2c/ccs/ccs-core.c b/drivers/media/i2c/ccs/ccs-core.c
index e21287d50c15..e1ae0f9fad43 100644
--- a/drivers/media/i2c/ccs/ccs-core.c
+++ b/drivers/media/i2c/ccs/ccs-core.c
@@ -674,7 +674,7 @@ static int ccs_set_ctrl(struct v4l2_ctrl *ctrl)
 		break;
 	}
 
-	pm_status = pm_runtime_get_if_active(&client->dev, true);
+	pm_status = pm_runtime_get_if_active(&client->dev);
 	if (!pm_status)
 		return 0;
 
diff --git a/drivers/media/i2c/ov64a40.c b/drivers/media/i2c/ov64a40.c
index 4fba4c2cb064..541bf74581d2 100644
--- a/drivers/media/i2c/ov64a40.c
+++ b/drivers/media/i2c/ov64a40.c
@@ -3287,7 +3287,7 @@ static int ov64a40_set_ctrl(struct v4l2_ctrl *ctrl)
 					 exp_max, 1, exp_val);
 	}
 
-	pm_status = pm_runtime_get_if_active(ov64a40->dev, true);
+	pm_status = pm_runtime_get_if_active(ov64a40->dev);
 	if (!pm_status)
 		return 0;
 
diff --git a/drivers/media/i2c/thp7312.c b/drivers/media/i2c/thp7312.c
index 2806887514dc..19bd923a7315 100644
--- a/drivers/media/i2c/thp7312.c
+++ b/drivers/media/i2c/thp7312.c
@@ -1052,7 +1052,7 @@ static int thp7312_s_ctrl(struct v4l2_ctrl *ctrl)
 	if (ctrl->flags & V4L2_CTRL_FLAG_INACTIVE)
 		return -EINVAL;
 
-	if (!pm_runtime_get_if_active(thp7312->dev, true))
+	if (!pm_runtime_get_if_active(thp7312->dev))
 		return 0;
 
 	switch (ctrl->id) {
diff --git a/drivers/net/ipa/ipa_smp2p.c b/drivers/net/ipa/ipa_smp2p.c
index 5620dc271fac..cbf3d4761ce3 100644
--- a/drivers/net/ipa/ipa_smp2p.c
+++ b/drivers/net/ipa/ipa_smp2p.c
@@ -92,7 +92,7 @@ static void ipa_smp2p_notify(struct ipa_smp2p *smp2p)
 		return;
 
 	dev = &smp2p->ipa->pdev->dev;
-	smp2p->power_on = pm_runtime_get_if_active(dev, true) > 0;
+	smp2p->power_on = pm_runtime_get_if_active(dev) > 0;
 
 	/* Signal whether the IPA power is enabled */
 	mask = BIT(smp2p->enabled_bit);
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index d8f11a078924..f8293ae71389 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2510,7 +2510,7 @@ static void pci_pme_list_scan(struct work_struct *work)
 			 * If the device is in a low power state it
 			 * should not be polled either.
 			 */
-			pm_status = pm_runtime_get_if_active(dev, true);
+			pm_status = pm_runtime_get_if_active(dev);
 			if (!pm_status)
 				continue;
 
diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h
index 7c9b35448563..436baa167498 100644
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -72,7 +72,8 @@ extern int pm_runtime_force_resume(struct device *dev);
 extern int __pm_runtime_idle(struct device *dev, int rpmflags);
 extern int __pm_runtime_suspend(struct device *dev, int rpmflags);
 extern int __pm_runtime_resume(struct device *dev, int rpmflags);
-extern int pm_runtime_get_if_active(struct device *dev, bool ign_usage_count);
+extern int pm_runtime_get_if_active(struct device *dev);
+extern int pm_runtime_get_if_in_use(struct device *dev);
 extern int pm_schedule_suspend(struct device *dev, unsigned int delay);
 extern int __pm_runtime_set_status(struct device *dev, unsigned int status);
 extern int pm_runtime_barrier(struct device *dev);
@@ -94,18 +95,6 @@ extern void pm_runtime_release_supplier(struct device_link *link);
 
 extern int devm_pm_runtime_enable(struct device *dev);
 
-/**
- * pm_runtime_get_if_in_use - Conditionally bump up runtime PM usage counter.
- * @dev: Target device.
- *
- * Increment the runtime PM usage counter of @dev if its runtime PM status is
- * %RPM_ACTIVE and its runtime PM usage counter is greater than 0.
- */
-static inline int pm_runtime_get_if_in_use(struct device *dev)
-{
-	return pm_runtime_get_if_active(dev, false);
-}
-
 /**
  * pm_suspend_ignore_children - Set runtime PM behavior regarding children.
  * @dev: Target device.
@@ -275,8 +264,7 @@ static inline int pm_runtime_get_if_in_use(struct device *dev)
 {
 	return -EINVAL;
 }
-static inline int pm_runtime_get_if_active(struct device *dev,
-					   bool ign_usage_count)
+static inline int pm_runtime_get_if_active(struct device *dev)
 {
 	return -EINVAL;
 }
diff --git a/sound/hda/hdac_device.c b/sound/hda/hdac_device.c
index 7f7b67fe1b65..068c16e52dff 100644
--- a/sound/hda/hdac_device.c
+++ b/sound/hda/hdac_device.c
@@ -612,7 +612,7 @@ EXPORT_SYMBOL_GPL(snd_hdac_power_up_pm);
 int snd_hdac_keep_power_up(struct hdac_device *codec)
 {
 	if (!atomic_inc_not_zero(&codec->in_pm)) {
-		int ret = pm_runtime_get_if_active(&codec->dev, true);
+		int ret = pm_runtime_get_if_active(&codec->dev);
 		if (!ret)
 			return -1;
 		if (ret < 0)
-- 
2.39.2