snd/hda, drm/i915: Track the display_power_status using a cookie

drm/i915 is tracking all wakeref owners with a cookie in order to
identify leaks. To that end, each rpm acquisition ops->get_power is
assigned a cookie which should be passed to ops->put_power to signify
its release (and removal from the list of wakeref owners). As snd/hda is
already using a bool to track current status of display_power extending
that to an unsigned long to hold the boolean cookie is a trivial
extension, and will quell all doubt that snd/hda is the cause of the
device runtime pm leaks.

v2: Keep using the power abstraction for local wakeref tracking.
v3: BUILD_BUG_ON impedance mismatch

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Jani Nikula <jani.nikula@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190213152109.16997-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c
index de26cd0..32dfd41 100644 (file)
--- a/drivers/gpu/drm/i915/intel_audio.c
+++ b/drivers/gpu/drm/i915/intel_audio.c
@@ -741,27 +741,31 @@ void intel_init_audio_hooks(struct drm_i915_private *dev_priv)
        }
 }
 
-static void i915_audio_component_get_power(struct device *kdev)
+static unsigned long i915_audio_component_get_power(struct device *kdev)
 {
-       intel_display_power_get(kdev_to_i915(kdev), POWER_DOMAIN_AUDIO);
+       /* Catch potential impedance mismatches before they occur! */
+       BUILD_BUG_ON(sizeof(intel_wakeref_t) > sizeof(unsigned long));
+
+       return intel_display_power_get(kdev_to_i915(kdev), POWER_DOMAIN_AUDIO);
 }
 
-static void i915_audio_component_put_power(struct device *kdev)
+static void i915_audio_component_put_power(struct device *kdev,
+                                          unsigned long cookie)
 {
-       intel_display_power_put_unchecked(kdev_to_i915(kdev),
-                                         POWER_DOMAIN_AUDIO);
+       intel_display_power_put(kdev_to_i915(kdev), POWER_DOMAIN_AUDIO, cookie);
 }
 
 static void i915_audio_component_codec_wake_override(struct device *kdev,
                                                     bool enable)
 {
        struct drm_i915_private *dev_priv = kdev_to_i915(kdev);
+       unsigned long cookie;
        u32 tmp;
 
        if (!IS_GEN(dev_priv, 9))
                return;
 
-       i915_audio_component_get_power(kdev);
+       cookie = i915_audio_component_get_power(kdev);
 
        /*
         * Enable/disable generating the codec wake signal, overriding the
@@ -779,7 +783,7 @@ static void i915_audio_component_codec_wake_override(struct device *kdev,
                usleep_range(1000, 1500);
        }
 
-       i915_audio_component_put_power(kdev);
+       i915_audio_component_put_power(kdev, cookie);
 }
 
 /* Get CDCLK in kHz  */
@@ -850,12 +854,13 @@ static int i915_audio_component_sync_audio_rate(struct device *kdev, int port,
        struct i915_audio_component *acomp = dev_priv->audio_component;
        struct intel_encoder *encoder;
        struct intel_crtc *crtc;
+       unsigned long cookie;
        int err = 0;
 
        if (!HAS_DDI(dev_priv))
                return 0;
 
-       i915_audio_component_get_power(kdev);
+       cookie = i915_audio_component_get_power(kdev);
        mutex_lock(&dev_priv->av_mutex);
 
        /* 1. get the pipe */
@@ -875,7 +880,7 @@ static int i915_audio_component_sync_audio_rate(struct device *kdev, int port,
 
  unlock:
        mutex_unlock(&dev_priv->av_mutex);
-       i915_audio_component_put_power(kdev);
+       i915_audio_component_put_power(kdev, cookie);
        return err;
 }
 

diff --git a/include/drm/drm_audio_component.h b/include/drm/drm_audio_component.h
index 4923b00..d0c7444 100644 (file)
--- a/include/drm/drm_audio_component.h
+++ b/include/drm/drm_audio_component.h
@@ -18,14 +18,17 @@ struct drm_audio_component_ops {
         * @get_power: get the POWER_DOMAIN_AUDIO power well
         *
         * Request the power well to be turned on.
+        *
+        * Returns a wakeref cookie to be passed back to the corresponding
+        * call to @put_power.
         */
-       void (*get_power)(struct device *);
+       unsigned long (*get_power)(struct device *);
        /**
         * @put_power: put the POWER_DOMAIN_AUDIO power well
         *
         * Allow the power well to be turned off.
         */
-       void (*put_power)(struct device *);
+       void (*put_power)(struct device *, unsigned long);
        /**
         * @codec_wake_override: Enable/disable codec wake signal
         */

diff --git a/include/sound/hdaudio.h b/include/sound/hdaudio.h
index b4fa1c7..a438ec8 100644 (file)
--- a/include/sound/hdaudio.h
+++ b/include/sound/hdaudio.h
@@ -367,7 +367,7 @@ struct hdac_bus {
        /* DRM component interface */
        struct drm_audio_component *audio_component;
        long display_power_status;
-       bool display_power_active;
+       unsigned long display_power_active;
 
        /* parameters required for enhanced capabilities */
        int num_streams;

diff --git a/sound/hda/hdac_component.c b/sound/hda/hdac_component.c
index a6d37b9..2702548 100644 (file)
--- a/sound/hda/hdac_component.c
+++ b/sound/hda/hdac_component.c
@@ -79,17 +79,23 @@ void snd_hdac_display_power(struct hdac_bus *bus, unsigned int idx, bool enable)
 
        if (bus->display_power_status) {
                if (!bus->display_power_active) {
+                       unsigned long cookie = -1;
+
                        if (acomp->ops->get_power)
-                               acomp->ops->get_power(acomp->dev);
+                               cookie = acomp->ops->get_power(acomp->dev);
+
                        snd_hdac_set_codec_wakeup(bus, true);
                        snd_hdac_set_codec_wakeup(bus, false);
-                       bus->display_power_active = true;
+                       bus->display_power_active = cookie;
                }
        } else {
                if (bus->display_power_active) {
+                       unsigned long cookie = bus->display_power_active;
+
                        if (acomp->ops->put_power)
-                               acomp->ops->put_power(acomp->dev);
-                       bus->display_power_active = false;
+                               acomp->ops->put_power(acomp->dev, cookie);
+
+                       bus->display_power_active = 0;
                }
        }
 }
@@ -325,9 +331,9 @@ int snd_hdac_acomp_exit(struct hdac_bus *bus)
                return 0;
 
        if (WARN_ON(bus->display_power_active) && acomp->ops)
-               acomp->ops->put_power(acomp->dev);
+               acomp->ops->put_power(acomp->dev, bus->display_power_active);
 
-       bus->display_power_active = false;
+       bus->display_power_active = 0;
        bus->display_power_status = 0;
 
        component_master_del(dev, &hdac_component_master_ops);