diff mbox series

[v2,3/3] drm/i915: Send hotplug event if edid had changed.

Message ID 20190628082454.16345-4-stanislav.lisovskiy@intel.com (mailing list archive)
State New, archived
Headers show
Series Send a hotplug when edid changes | expand

Commit Message

Lisovskiy, Stanislav June 28, 2019, 8:24 a.m. UTC
Added edid checking to dp and hdmi edid setting functions, which
are called from detect hooks. The result currently is propagated
to calling layer using drm_connector->change_counter(proposed by Daniel Vetter).
drm_helper_hpd_irq_event and intel_encoder_hotplug are currently both
responsible for checking if this counter or connection status is changed.

There are conflicting parts in drm and i915 which attempt
to do the same job - drm_helper_hpd_irq_event attempts to
check connector status changes and then call hotplug,
just as i915_hotplug_work_func, which calls encoder->hotplug
hook which in turn calls generic intel_encoder_hotplug function
which attempts to probe if output has changed.
Looks like both needs to be changed, so added edid checking
also to intel_encoder_hotplug function which is called both
for hdmi and dp.

v2: Renamed change counter to epoch counter. Fixed type name.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105540
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c      | 16 +++++++++++++++-
 drivers/gpu/drm/i915/display/intel_hdmi.c    | 16 +++++++++++++---
 drivers/gpu/drm/i915/display/intel_hotplug.c | 20 +++++++++++++++-----
 3 files changed, 43 insertions(+), 9 deletions(-)

Comments

Ramalingam C June 28, 2019, 4:24 a.m. UTC | #1
On 2019-06-28 at 11:24:54 +0300, Stanislav Lisovskiy wrote:
> Added edid checking to dp and hdmi edid setting functions, which
> are called from detect hooks. The result currently is propagated
> to calling layer using drm_connector->change_counter(proposed by Daniel Vetter).
> drm_helper_hpd_irq_event and intel_encoder_hotplug are currently both
> responsible for checking if this counter or connection status is changed.
> 
> There are conflicting parts in drm and i915 which attempt
> to do the same job - drm_helper_hpd_irq_event attempts to
> check connector status changes and then call hotplug,
> just as i915_hotplug_work_func, which calls encoder->hotplug
> hook which in turn calls generic intel_encoder_hotplug function
> which attempts to probe if output has changed.
> Looks like both needs to be changed, so added edid checking
> also to intel_encoder_hotplug function which is called both
> for hdmi and dp.
> 
> v2: Renamed change counter to epoch counter. Fixed type name.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105540
> Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp.c      | 16 +++++++++++++++-
>  drivers/gpu/drm/i915/display/intel_hdmi.c    | 16 +++++++++++++---
>  drivers/gpu/drm/i915/display/intel_hotplug.c | 20 +++++++++++++++-----
>  3 files changed, 43 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 4336df46fe78..c2ed02478cf9 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -5510,10 +5510,24 @@ static void
>  intel_dp_set_edid(struct intel_dp *intel_dp)
>  {
>  	struct intel_connector *intel_connector = intel_dp->attached_connector;
> +	struct drm_connector *connector = &intel_connector->base;
>  	struct edid *edid;
> +	struct edid *old_edid;
>  
> -	intel_dp_unset_edid(intel_dp);
>  	edid = intel_dp_get_edid(intel_dp);
> +	old_edid = intel_connector->detect_edid;
> +
> +	if (!drm_edid_are_equal(edid, old_edid)) {
> +		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] Edid was changed! Updating blob property.\n",
> +		    connector->base.id, connector->name);
> +
> +		connector->epoch_counter += 1;
> +		DRM_DEBUG_KMS("Updating change counter to %llu\n", connector->epoch_counter);
> +
> +		intel_connector_update_modes(&intel_connector->base, edid);
> +	}
> +
> +	intel_dp_unset_edid(intel_dp);
>  	intel_connector->detect_edid = edid;
>  
>  	intel_dp->has_audio = drm_detect_monitor_audio(edid);
> diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
> index 0ebec69bbbfc..f892c7b795ce 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
> @@ -2503,7 +2503,7 @@ intel_hdmi_set_edid(struct drm_connector *connector)
>  	struct drm_i915_private *dev_priv = to_i915(connector->dev);
>  	struct intel_hdmi *intel_hdmi = intel_attached_hdmi(connector);
>  	intel_wakeref_t wakeref;
> -	struct edid *edid;
> +	struct edid *edid, *old_edid;
>  	bool connected = false;
>  	struct i2c_adapter *i2c;
>  
> @@ -2524,11 +2524,22 @@ intel_hdmi_set_edid(struct drm_connector *connector)
>  
>  	intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS, wakeref);
>  
> +	old_edid = to_intel_connector(connector)->detect_edid;
> +
> +	if (!drm_edid_are_equal(edid, old_edid)) {
> +		intel_connector_update_modes(connector, edid);
> +		DRM_DEBUG_KMS("Updating change counter to %llu\n", connector->epoch_counter);
> +		connector->epoch_counter += 1;
> +
> +		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] Edid was changed! Updating blob property.\n",
> +		    connector->base.id, connector->name);
> +	}
> +	intel_hdmi_unset_edid(connector);
>  	to_intel_connector(connector)->detect_edid = edid;
> +
This and next changes are unrelated with this commit. Might want to keep
it for separate patch.

-Ram
>  	if (edid && edid->input & DRM_EDID_INPUT_DIGITAL) {
>  		intel_hdmi->has_audio = drm_detect_monitor_audio(edid);
>  		intel_hdmi->has_hdmi_sink = drm_detect_hdmi_monitor(edid);
> -
>  		connected = true;
>  	}
>  
> @@ -2555,7 +2566,6 @@ intel_hdmi_detect(struct drm_connector *connector, bool force)
>  	    !intel_digital_port_connected(encoder))
>  		goto out;
>  
> -	intel_hdmi_unset_edid(connector);
>  
>  	if (intel_hdmi_set_edid(connector))
>  		status = connector_status_connected;
> diff --git a/drivers/gpu/drm/i915/display/intel_hotplug.c b/drivers/gpu/drm/i915/display/intel_hotplug.c
> index ea3de4acc850..f9d9e963196a 100644
> --- a/drivers/gpu/drm/i915/display/intel_hotplug.c
> +++ b/drivers/gpu/drm/i915/display/intel_hotplug.c
> @@ -271,23 +271,33 @@ bool intel_encoder_hotplug(struct intel_encoder *encoder,
>  {
>  	struct drm_device *dev = connector->base.dev;
>  	enum drm_connector_status old_status;
> +	u64 old_epoch_counter;
> +	bool ret = false;
>  
>  	WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
>  	old_status = connector->base.status;
>  
> +	old_epoch_counter = connector->base.epoch_counter;
> +
>  	connector->base.status =
>  		drm_helper_probe_detect(&connector->base, NULL, false);
>  
> -	if (old_status == connector->base.status)
> -		return false;
> +	if (old_epoch_counter != connector->base.epoch_counter)
> +		ret = true;
>  
> -	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
> +	if (old_status != connector->base.status)
> +		ret = true;
> +
> +	if (ret) {
> +		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s(change counter %llu)\n",
>  		      connector->base.base.id,
>  		      connector->base.name,
>  		      drm_get_connector_status_name(old_status),
> -		      drm_get_connector_status_name(connector->base.status));
> +		      drm_get_connector_status_name(connector->base.status),
> +		      connector->base.epoch_counter);
> +	}
>  
> -	return true;
> +	return ret;
>  }
>  
>  static bool intel_encoder_has_hpd_pulse(struct intel_encoder *encoder)
> -- 
> 2.17.1
>
Ramalingam C June 28, 2019, 4:50 a.m. UTC | #2
On 2019-06-28 at 17:06:09 +0530, Lisovskiy, Stanislav wrote:
> On Fri, 2019-06-28 at 09:54 +0530, Ramalingam C wrote:
> > On 2019-06-28 at 11:24:54 +0300, Stanislav Lisovskiy wrote:
> > > Added edid checking to dp and hdmi edid setting functions, which
> > > are called from detect hooks. The result currently is propagated
> > > to calling layer using drm_connector->change_counter(proposed by
> > > Daniel Vetter).
> > > drm_helper_hpd_irq_event and intel_encoder_hotplug are currently
> > > both
> > > responsible for checking if this counter or connection status is
> > > changed.
> > > 
> > > There are conflicting parts in drm and i915 which attempt
> > > to do the same job - drm_helper_hpd_irq_event attempts to
> > > check connector status changes and then call hotplug,
> > > just as i915_hotplug_work_func, which calls encoder->hotplug
> > > hook which in turn calls generic intel_encoder_hotplug function
> > > which attempts to probe if output has changed.
> > > Looks like both needs to be changed, so added edid checking
> > > also to intel_encoder_hotplug function which is called both
> > > for hdmi and dp.
> > > 
> > > v2: Renamed change counter to epoch counter. Fixed type name.
> > > 
> > > 
> 
> > > @@ -2524,11 +2524,22 @@ intel_hdmi_set_edid(struct drm_connector
> > > *connector)
> > >  
> > >  	intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS, wakeref);
> > >  
> > > +	old_edid = to_intel_connector(connector)->detect_edid;
> > > +
> > > +	if (!drm_edid_are_equal(edid, old_edid)) {
> > > +		intel_connector_update_modes(connector, edid);
> > > +		DRM_DEBUG_KMS("Updating change counter to %llu\n",
> > > connector->epoch_counter);
> > > +		connector->epoch_counter += 1;
> > > +
> > > +		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] Edid was changed!
> > > Updating blob property.\n",
> > > +		    connector->base.id, connector->name);
> > > +	}
> > > +	intel_hdmi_unset_edid(connector);
> > >  	to_intel_connector(connector)->detect_edid = edid;
> > > +
> 
> > 
> > This and next changes are unrelated with this commit. Might want to
> > keep
> > it for separate patch.
> 
> What do you mean by unrelated? I thought dependent changes should go in
> one patch series and here we are taking into use epoch_counter for
> i915, which was introduced in previous 2 separate drm patches from that
> series.
> 
> The drm changes should obviously always go first here, otherwise this
> patch will fail - I wouldn't even be able to send it for testing if
> that would be in another series.
Meant the new line addition and line removal. just usual suggestions.
you can ignore if you prefer. apart from that changes looks good.

-Ram
> 
> > 
> > -Ram
> > >  	if (edid && edid->input & DRM_EDID_INPUT_DIGITAL) {
> > >  		intel_hdmi->has_audio = drm_detect_monitor_audio(edid);
> > >  		intel_hdmi->has_hdmi_sink =
> > > drm_detect_hdmi_monitor(edid);
> > > -
> > >  		connected = true;
> > >  	}
> > >  
> > > @@ -2555,7 +2566,6 @@ intel_hdmi_detect(struct drm_connector
> > > *connector, bool force)
> > >  	    !intel_digital_port_connected(encoder))
> > >  		goto out;
> > >  
> > > -	intel_hdmi_unset_edid(connector);
> > >  
> > >  	if (intel_hdmi_set_edid(connector))
> > >  		status = connector_status_connected;
> > > diff --git a/drivers/gpu/drm/i915/display/intel_hotplug.c
> > > b/drivers/gpu/drm/i915/display/intel_hotplug.c
> > > index ea3de4acc850..f9d9e963196a 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_hotplug.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_hotplug.c
> > > @@ -271,23 +271,33 @@ bool intel_encoder_hotplug(struct
> > > intel_encoder *encoder,
> > >  {
> > >  	struct drm_device *dev = connector->base.dev;
> > >  	enum drm_connector_status old_status;
> > > +	u64 old_epoch_counter;
> > > +	bool ret = false;
> > >  
> > >  	WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
> > >  	old_status = connector->base.status;
> > >  
> > > +	old_epoch_counter = connector->base.epoch_counter;
> > > +
> > >  	connector->base.status =
> > >  		drm_helper_probe_detect(&connector->base, NULL, false);
> > >  
> > > -	if (old_status == connector->base.status)
> > > -		return false;
> > > +	if (old_epoch_counter != connector->base.epoch_counter)
> > > +		ret = true;
> > >  
> > > -	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to
> > > %s\n",
> > > +	if (old_status != connector->base.status)
> > > +		ret = true;
> > > +
> > > +	if (ret) {
> > > +		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s
> > > to %s(change counter %llu)\n",
> > >  		      connector->base.base.id,
> > >  		      connector->base.name,
> > >  		      drm_get_connector_status_name(old_status),
> > > -		      drm_get_connector_status_name(connector-
> > > >base.status));
> > > +		      drm_get_connector_status_name(connector-
> > > >base.status),
> > > +		      connector->base.epoch_counter);
> > > +	}
> > >  
> > > -	return true;
> > > +	return ret;
> > >  }
> > >  
> > >  static bool intel_encoder_has_hpd_pulse(struct intel_encoder
> > > *encoder)
> > > -- 
> > > 2.17.1
> > >
Lisovskiy, Stanislav June 28, 2019, 11:36 a.m. UTC | #3
On Fri, 2019-06-28 at 09:54 +0530, Ramalingam C wrote:
> On 2019-06-28 at 11:24:54 +0300, Stanislav Lisovskiy wrote:
> > Added edid checking to dp and hdmi edid setting functions, which
> > are called from detect hooks. The result currently is propagated
> > to calling layer using drm_connector->change_counter(proposed by
> > Daniel Vetter).
> > drm_helper_hpd_irq_event and intel_encoder_hotplug are currently
> > both
> > responsible for checking if this counter or connection status is
> > changed.
> > 
> > There are conflicting parts in drm and i915 which attempt
> > to do the same job - drm_helper_hpd_irq_event attempts to
> > check connector status changes and then call hotplug,
> > just as i915_hotplug_work_func, which calls encoder->hotplug
> > hook which in turn calls generic intel_encoder_hotplug function
> > which attempts to probe if output has changed.
> > Looks like both needs to be changed, so added edid checking
> > also to intel_encoder_hotplug function which is called both
> > for hdmi and dp.
> > 
> > v2: Renamed change counter to epoch counter. Fixed type name.
> > 
> > 

> > @@ -2524,11 +2524,22 @@ intel_hdmi_set_edid(struct drm_connector
> > *connector)
> >  
> >  	intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS, wakeref);
> >  
> > +	old_edid = to_intel_connector(connector)->detect_edid;
> > +
> > +	if (!drm_edid_are_equal(edid, old_edid)) {
> > +		intel_connector_update_modes(connector, edid);
> > +		DRM_DEBUG_KMS("Updating change counter to %llu\n",
> > connector->epoch_counter);
> > +		connector->epoch_counter += 1;
> > +
> > +		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] Edid was changed!
> > Updating blob property.\n",
> > +		    connector->base.id, connector->name);
> > +	}
> > +	intel_hdmi_unset_edid(connector);
> >  	to_intel_connector(connector)->detect_edid = edid;
> > +

> 
> This and next changes are unrelated with this commit. Might want to
> keep
> it for separate patch.

What do you mean by unrelated? I thought dependent changes should go in
one patch series and here we are taking into use epoch_counter for
i915, which was introduced in previous 2 separate drm patches from that
series.

The drm changes should obviously always go first here, otherwise this
patch will fail - I wouldn't even be able to send it for testing if
that would be in another series.

> 
> -Ram
> >  	if (edid && edid->input & DRM_EDID_INPUT_DIGITAL) {
> >  		intel_hdmi->has_audio = drm_detect_monitor_audio(edid);
> >  		intel_hdmi->has_hdmi_sink =
> > drm_detect_hdmi_monitor(edid);
> > -
> >  		connected = true;
> >  	}
> >  
> > @@ -2555,7 +2566,6 @@ intel_hdmi_detect(struct drm_connector
> > *connector, bool force)
> >  	    !intel_digital_port_connected(encoder))
> >  		goto out;
> >  
> > -	intel_hdmi_unset_edid(connector);
> >  
> >  	if (intel_hdmi_set_edid(connector))
> >  		status = connector_status_connected;
> > diff --git a/drivers/gpu/drm/i915/display/intel_hotplug.c
> > b/drivers/gpu/drm/i915/display/intel_hotplug.c
> > index ea3de4acc850..f9d9e963196a 100644
> > --- a/drivers/gpu/drm/i915/display/intel_hotplug.c
> > +++ b/drivers/gpu/drm/i915/display/intel_hotplug.c
> > @@ -271,23 +271,33 @@ bool intel_encoder_hotplug(struct
> > intel_encoder *encoder,
> >  {
> >  	struct drm_device *dev = connector->base.dev;
> >  	enum drm_connector_status old_status;
> > +	u64 old_epoch_counter;
> > +	bool ret = false;
> >  
> >  	WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
> >  	old_status = connector->base.status;
> >  
> > +	old_epoch_counter = connector->base.epoch_counter;
> > +
> >  	connector->base.status =
> >  		drm_helper_probe_detect(&connector->base, NULL, false);
> >  
> > -	if (old_status == connector->base.status)
> > -		return false;
> > +	if (old_epoch_counter != connector->base.epoch_counter)
> > +		ret = true;
> >  
> > -	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to
> > %s\n",
> > +	if (old_status != connector->base.status)
> > +		ret = true;
> > +
> > +	if (ret) {
> > +		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s
> > to %s(change counter %llu)\n",
> >  		      connector->base.base.id,
> >  		      connector->base.name,
> >  		      drm_get_connector_status_name(old_status),
> > -		      drm_get_connector_status_name(connector-
> > >base.status));
> > +		      drm_get_connector_status_name(connector-
> > >base.status),
> > +		      connector->base.epoch_counter);
> > +	}
> >  
> > -	return true;
> > +	return ret;
> >  }
> >  
> >  static bool intel_encoder_has_hpd_pulse(struct intel_encoder
> > *encoder)
> > -- 
> > 2.17.1
> >
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 4336df46fe78..c2ed02478cf9 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5510,10 +5510,24 @@  static void
 intel_dp_set_edid(struct intel_dp *intel_dp)
 {
 	struct intel_connector *intel_connector = intel_dp->attached_connector;
+	struct drm_connector *connector = &intel_connector->base;
 	struct edid *edid;
+	struct edid *old_edid;
 
-	intel_dp_unset_edid(intel_dp);
 	edid = intel_dp_get_edid(intel_dp);
+	old_edid = intel_connector->detect_edid;
+
+	if (!drm_edid_are_equal(edid, old_edid)) {
+		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] Edid was changed! Updating blob property.\n",
+		    connector->base.id, connector->name);
+
+		connector->epoch_counter += 1;
+		DRM_DEBUG_KMS("Updating change counter to %llu\n", connector->epoch_counter);
+
+		intel_connector_update_modes(&intel_connector->base, edid);
+	}
+
+	intel_dp_unset_edid(intel_dp);
 	intel_connector->detect_edid = edid;
 
 	intel_dp->has_audio = drm_detect_monitor_audio(edid);
diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index 0ebec69bbbfc..f892c7b795ce 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -2503,7 +2503,7 @@  intel_hdmi_set_edid(struct drm_connector *connector)
 	struct drm_i915_private *dev_priv = to_i915(connector->dev);
 	struct intel_hdmi *intel_hdmi = intel_attached_hdmi(connector);
 	intel_wakeref_t wakeref;
-	struct edid *edid;
+	struct edid *edid, *old_edid;
 	bool connected = false;
 	struct i2c_adapter *i2c;
 
@@ -2524,11 +2524,22 @@  intel_hdmi_set_edid(struct drm_connector *connector)
 
 	intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS, wakeref);
 
+	old_edid = to_intel_connector(connector)->detect_edid;
+
+	if (!drm_edid_are_equal(edid, old_edid)) {
+		intel_connector_update_modes(connector, edid);
+		DRM_DEBUG_KMS("Updating change counter to %llu\n", connector->epoch_counter);
+		connector->epoch_counter += 1;
+
+		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] Edid was changed! Updating blob property.\n",
+		    connector->base.id, connector->name);
+	}
+	intel_hdmi_unset_edid(connector);
 	to_intel_connector(connector)->detect_edid = edid;
+
 	if (edid && edid->input & DRM_EDID_INPUT_DIGITAL) {
 		intel_hdmi->has_audio = drm_detect_monitor_audio(edid);
 		intel_hdmi->has_hdmi_sink = drm_detect_hdmi_monitor(edid);
-
 		connected = true;
 	}
 
@@ -2555,7 +2566,6 @@  intel_hdmi_detect(struct drm_connector *connector, bool force)
 	    !intel_digital_port_connected(encoder))
 		goto out;
 
-	intel_hdmi_unset_edid(connector);
 
 	if (intel_hdmi_set_edid(connector))
 		status = connector_status_connected;
diff --git a/drivers/gpu/drm/i915/display/intel_hotplug.c b/drivers/gpu/drm/i915/display/intel_hotplug.c
index ea3de4acc850..f9d9e963196a 100644
--- a/drivers/gpu/drm/i915/display/intel_hotplug.c
+++ b/drivers/gpu/drm/i915/display/intel_hotplug.c
@@ -271,23 +271,33 @@  bool intel_encoder_hotplug(struct intel_encoder *encoder,
 {
 	struct drm_device *dev = connector->base.dev;
 	enum drm_connector_status old_status;
+	u64 old_epoch_counter;
+	bool ret = false;
 
 	WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 	old_status = connector->base.status;
 
+	old_epoch_counter = connector->base.epoch_counter;
+
 	connector->base.status =
 		drm_helper_probe_detect(&connector->base, NULL, false);
 
-	if (old_status == connector->base.status)
-		return false;
+	if (old_epoch_counter != connector->base.epoch_counter)
+		ret = true;
 
-	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
+	if (old_status != connector->base.status)
+		ret = true;
+
+	if (ret) {
+		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s(change counter %llu)\n",
 		      connector->base.base.id,
 		      connector->base.name,
 		      drm_get_connector_status_name(old_status),
-		      drm_get_connector_status_name(connector->base.status));
+		      drm_get_connector_status_name(connector->base.status),
+		      connector->base.epoch_counter);
+	}
 
-	return true;
+	return ret;
 }
 
 static bool intel_encoder_has_hpd_pulse(struct intel_encoder *encoder)