Re: [PATCH v3 1/2] pm: runtime: Simplify pm_runtime_get_if_active() usage

Alex Elder <elder@xxxxxxxx> · Fri, 26 Jan 2024 09:12:02 -0600

On 1/22/24 5:41 AM, Sakari Ailus wrote:
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 explitly 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 renamed as
pm_runtime_get_conditional().

Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Reviewed-by: Alex Elder <elder@xxxxxxxxxx> # drivers/net/ipa/ipa_smp2p.c

I actually intended my "Reviewed-by" to cover the entire patch.  I
checked every caller and they all looked good to me.

					-Alex

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Acked-by: Takashi Iwai <tiwai@xxxxxxx> # sound/
Reviewed-by: Jacek Lawrynowicz <jacek.lawrynowicz@xxxxxxxxxxxxxxx> # drivers/accel/ivpu/
Acked-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> # drivers/gpu/drm/i915/
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
---
  Documentation/power/runtime_pm.rst      |  5 ++--
  drivers/accel/ivpu/ivpu_pm.c            |  2 +-
  drivers/base/power/runtime.c            | 10 +++++---
  drivers/gpu/drm/i915/intel_runtime_pm.c |  2 +-
  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              | 32 +++++++++++++++++++++----
  sound/hda/hdac_device.c                 |  2 +-
  12 files changed, 45 insertions(+), 20 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..b4cb3f19b0d8 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.
   *
@@ -1196,8 +1196,12 @@ 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.
+ *
+ * This function is not primarily intended for use in drivers, most of which are
+ * better served by either pm_runtime_get_if_active() or
+ * pm_runtime_get_if_in_use() instead.
   */
-int pm_runtime_get_if_active(struct device *dev, bool ign_usage_count)
+int pm_runtime_get_conditional(struct device *dev, bool ign_usage_count)
  {
  	unsigned long flags;
  	int retval;
@@ -1218,7 +1222,7 @@ int pm_runtime_get_if_active(struct device *dev, bool ign_usage_count)
  
  	return retval;
  }
-EXPORT_SYMBOL_GPL(pm_runtime_get_if_active);
+EXPORT_SYMBOL_GPL(pm_runtime_get_conditional);
  
  /**
   * __pm_runtime_set_status - Set runtime PM status of a device.
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 860b51b56a92..b5f8abd2a22b 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -246,7 +246,7 @@ 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 (pm_runtime_get_conditional(rpm->kdev, ignore_usecount) <= 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..a212b3008ade 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_conditional(struct device *dev,
+					bool ign_usage_count);
  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);
@@ -94,16 +95,33 @@ extern void pm_runtime_release_supplier(struct device_link *link);
  
  extern int devm_pm_runtime_enable(struct device *dev);
  
+/**
+ * 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.
+ */
+static inline int pm_runtime_get_if_active(struct device *dev)
+{
+	return pm_runtime_get_conditional(dev, true);
+}
+
  /**
   * 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.
+ * %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.
   */
  static inline int pm_runtime_get_if_in_use(struct device *dev)
  {
-	return pm_runtime_get_if_active(dev, false);
+	return pm_runtime_get_conditional(dev, false);
  }
  
  /**
@@ -275,8 +293,12 @@ 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;
+}
+static inline int pm_runtime_get_conditional(struct device *dev,
+					     bool ign_usage_count)
  {
  	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)







