[PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Bjorn Andersson]

In some implementations, such as the Qualcomm platforms, the display
driver has no way to query the current HPD state and as such it's
impossible to distinguish between disconnect and attention events.

Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
state.

Also push the test for unchanged state in the displayport altmode driver
into the i915 driver, to allow other drivers to act upon each update.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---

Note that the Intel driver has only been compile tested with this patch.

 drivers/gpu/drm/drm_connector.c          |  6 ++++--
 drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
 drivers/gpu/drm/i915/i915_drv.h          |  3 +++
 drivers/usb/typec/altmodes/displayport.c |  9 ++-------
 include/drm/drm_connector.h              |  5 +++--
 5 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index a50c82bc2b2f..ad7295597c0f 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
 /**
  * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
  * @connector_fwnode: fwnode_handle to report the event on
+ * @hpd_state: number of data lanes available
  *
  * On some hardware a hotplug event notification may come from outside the display
  * driver / device. An example of this is some USB Type-C setups where the hardware
@@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
  * This function can be used to report these out-of-band events after obtaining
  * a drm_connector reference through calling drm_connector_find_by_fwnode().
  */
-void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
+void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
+				     bool hpd_state)
 {
 	struct drm_connector *connector;
 
@@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
 		return;
 
 	if (connector->funcs->oob_hotplug_event)
-		connector->funcs->oob_hotplug_event(connector);
+		connector->funcs->oob_hotplug_event(connector, hpd_state);
 
 	drm_connector_put(connector);
 }
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 146b83916005..00520867d37b 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
 	return intel_modeset_synced_crtcs(state, conn);
 }
 
-static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
+static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
 {
 	struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
 	struct drm_i915_private *i915 = to_i915(connector->dev);
+	bool need_work = false;
 
 	spin_lock_irq(&i915->irq_lock);
-	i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
+	if (hpd_state != i915->hotplug.oob_hotplug_state) {
+		i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
+
+		i915->hotplug.oob_hotplug_state = hpd_state;
+		need_work = true;
+	}
 	spin_unlock_irq(&i915->irq_lock);
-	queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
+
+	if (need_work)
+		queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
 }
 
 static const struct drm_connector_funcs intel_dp_connector_funcs = {
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 8c1706fd81f9..543ebf1cfcf4 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -149,6 +149,9 @@ struct i915_hotplug {
 	/* Whether or not to count short HPD IRQs in HPD storms */
 	u8 hpd_short_storm_enabled;
 
+	/* Last state reported by oob_hotplug_event */
+	bool oob_hotplug_state;
+
 	/*
 	 * if we get a HPD irq from DP and a HPD irq from non-DP
 	 * the non-DP HPD could block the workqueue on a mode config
diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
index c1d8c23baa39..a4596be4d34a 100644
--- a/drivers/usb/typec/altmodes/displayport.c
+++ b/drivers/usb/typec/altmodes/displayport.c
@@ -59,7 +59,6 @@ struct dp_altmode {
 	struct typec_displayport_data data;
 
 	enum dp_state state;
-	bool hpd;
 
 	struct mutex lock; /* device lock */
 	struct work_struct work;
@@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
 		if (!ret)
 			dp->state = DP_STATE_CONFIGURE;
 	} else {
-		if (dp->hpd != hpd) {
-			drm_connector_oob_hotplug_event(dp->connector_fwnode);
-			dp->hpd = hpd;
-		}
+		drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
 	}
 
 	return ret;
@@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
 	cancel_work_sync(&dp->work);
 
 	if (dp->connector_fwnode) {
-		if (dp->hpd)
-			drm_connector_oob_hotplug_event(dp->connector_fwnode);
+		drm_connector_oob_hotplug_event(dp->connector_fwnode, false);
 
 		fwnode_handle_put(dp->connector_fwnode);
 	}
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 64cf5f88c05b..7c90b8eb2ace 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -1141,7 +1141,7 @@ struct drm_connector_funcs {
 	 * This will get called when a hotplug-event for a drm-connector
 	 * has been received from a source outside the display driver / device.
 	 */
-	void (*oob_hotplug_event)(struct drm_connector *connector);
+	void (*oob_hotplug_event)(struct drm_connector *connector, bool hpd_state);
 };
 
 /**
@@ -1742,7 +1742,8 @@ drm_connector_is_unregistered(struct drm_connector *connector)
 		DRM_CONNECTOR_UNREGISTERED;
 }
 
-void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode);
+void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
+				     bool hpd_state);
 const char *drm_get_connector_type_name(unsigned int connector_type);
 const char *drm_get_connector_status_name(enum drm_connector_status status);
 const char *drm_get_subpixel_order_name(enum subpixel_order order);
-- 
2.33.1

[PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Bjorn Andersson]

In some implementations, such as the Qualcomm platforms, the display
driver has no way to query the current HPD state and as such it's
impossible to distinguish between disconnect and attention events.

Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
state.

Also push the test for unchanged state in the displayport altmode driver
into the i915 driver, to allow other drivers to act upon each update.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---

Note that the Intel driver has only been compile tested with this patch.

 drivers/gpu/drm/drm_connector.c          |  6 ++++--
 drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
 drivers/gpu/drm/i915/i915_drv.h          |  3 +++
 drivers/usb/typec/altmodes/displayport.c |  9 ++-------
 include/drm/drm_connector.h              |  5 +++--
 5 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index a50c82bc2b2f..ad7295597c0f 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
 /**
  * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
  * @connector_fwnode: fwnode_handle to report the event on
+ * @hpd_state: number of data lanes available
  *
  * On some hardware a hotplug event notification may come from outside the display
  * driver / device. An example of this is some USB Type-C setups where the hardware
@@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
  * This function can be used to report these out-of-band events after obtaining
  * a drm_connector reference through calling drm_connector_find_by_fwnode().
  */
-void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
+void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
+				     bool hpd_state)
 {
 	struct drm_connector *connector;
 
@@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
 		return;
 
 	if (connector->funcs->oob_hotplug_event)
-		connector->funcs->oob_hotplug_event(connector);
+		connector->funcs->oob_hotplug_event(connector, hpd_state);
 
 	drm_connector_put(connector);
 }
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 146b83916005..00520867d37b 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
 	return intel_modeset_synced_crtcs(state, conn);
 }
 
-static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
+static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
 {
 	struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
 	struct drm_i915_private *i915 = to_i915(connector->dev);
+	bool need_work = false;
 
 	spin_lock_irq(&i915->irq_lock);
-	i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
+	if (hpd_state != i915->hotplug.oob_hotplug_state) {
+		i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
+
+		i915->hotplug.oob_hotplug_state = hpd_state;
+		need_work = true;
+	}
 	spin_unlock_irq(&i915->irq_lock);
-	queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
+
+	if (need_work)
+		queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
 }
 
 static const struct drm_connector_funcs intel_dp_connector_funcs = {
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 8c1706fd81f9..543ebf1cfcf4 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -149,6 +149,9 @@ struct i915_hotplug {
 	/* Whether or not to count short HPD IRQs in HPD storms */
 	u8 hpd_short_storm_enabled;
 
+	/* Last state reported by oob_hotplug_event */
+	bool oob_hotplug_state;
+
 	/*
 	 * if we get a HPD irq from DP and a HPD irq from non-DP
 	 * the non-DP HPD could block the workqueue on a mode config
diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
index c1d8c23baa39..a4596be4d34a 100644
--- a/drivers/usb/typec/altmodes/displayport.c
+++ b/drivers/usb/typec/altmodes/displayport.c
@@ -59,7 +59,6 @@ struct dp_altmode {
 	struct typec_displayport_data data;
 
 	enum dp_state state;
-	bool hpd;
 
 	struct mutex lock; /* device lock */
 	struct work_struct work;
@@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
 		if (!ret)
 			dp->state = DP_STATE_CONFIGURE;
 	} else {
-		if (dp->hpd != hpd) {
-			drm_connector_oob_hotplug_event(dp->connector_fwnode);
-			dp->hpd = hpd;
-		}
+		drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
 	}
 
 	return ret;
@@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
 	cancel_work_sync(&dp->work);
 
 	if (dp->connector_fwnode) {
-		if (dp->hpd)
-			drm_connector_oob_hotplug_event(dp->connector_fwnode);
+		drm_connector_oob_hotplug_event(dp->connector_fwnode, false);
 
 		fwnode_handle_put(dp->connector_fwnode);
 	}
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 64cf5f88c05b..7c90b8eb2ace 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -1141,7 +1141,7 @@ struct drm_connector_funcs {
 	 * This will get called when a hotplug-event for a drm-connector
 	 * has been received from a source outside the display driver / device.
 	 */
-	void (*oob_hotplug_event)(struct drm_connector *connector);
+	void (*oob_hotplug_event)(struct drm_connector *connector, bool hpd_state);
 };
 
 /**
@@ -1742,7 +1742,8 @@ drm_connector_is_unregistered(struct drm_connector *connector)
 		DRM_CONNECTOR_UNREGISTERED;
 }
 
-void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode);
+void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
+				     bool hpd_state);
 const char *drm_get_connector_type_name(unsigned int connector_type);
 const char *drm_get_connector_status_name(enum drm_connector_status status);
 const char *drm_get_subpixel_order_name(enum subpixel_order order);
-- 
2.33.1

[Intel-gfx] [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Bjorn Andersson]

In some implementations, such as the Qualcomm platforms, the display
driver has no way to query the current HPD state and as such it's
impossible to distinguish between disconnect and attention events.

Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
state.

Also push the test for unchanged state in the displayport altmode driver
into the i915 driver, to allow other drivers to act upon each update.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---

Note that the Intel driver has only been compile tested with this patch.

 drivers/gpu/drm/drm_connector.c          |  6 ++++--
 drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
 drivers/gpu/drm/i915/i915_drv.h          |  3 +++
 drivers/usb/typec/altmodes/displayport.c |  9 ++-------
 include/drm/drm_connector.h              |  5 +++--
 5 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index a50c82bc2b2f..ad7295597c0f 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
 /**
  * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
  * @connector_fwnode: fwnode_handle to report the event on
+ * @hpd_state: number of data lanes available
  *
  * On some hardware a hotplug event notification may come from outside the display
  * driver / device. An example of this is some USB Type-C setups where the hardware
@@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
  * This function can be used to report these out-of-band events after obtaining
  * a drm_connector reference through calling drm_connector_find_by_fwnode().
  */
-void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
+void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
+				     bool hpd_state)
 {
 	struct drm_connector *connector;
 
@@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
 		return;
 
 	if (connector->funcs->oob_hotplug_event)
-		connector->funcs->oob_hotplug_event(connector);
+		connector->funcs->oob_hotplug_event(connector, hpd_state);
 
 	drm_connector_put(connector);
 }
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 146b83916005..00520867d37b 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
 	return intel_modeset_synced_crtcs(state, conn);
 }
 
-static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
+static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
 {
 	struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
 	struct drm_i915_private *i915 = to_i915(connector->dev);
+	bool need_work = false;
 
 	spin_lock_irq(&i915->irq_lock);
-	i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
+	if (hpd_state != i915->hotplug.oob_hotplug_state) {
+		i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
+
+		i915->hotplug.oob_hotplug_state = hpd_state;
+		need_work = true;
+	}
 	spin_unlock_irq(&i915->irq_lock);
-	queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
+
+	if (need_work)
+		queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
 }
 
 static const struct drm_connector_funcs intel_dp_connector_funcs = {
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 8c1706fd81f9..543ebf1cfcf4 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -149,6 +149,9 @@ struct i915_hotplug {
 	/* Whether or not to count short HPD IRQs in HPD storms */
 	u8 hpd_short_storm_enabled;
 
+	/* Last state reported by oob_hotplug_event */
+	bool oob_hotplug_state;
+
 	/*
 	 * if we get a HPD irq from DP and a HPD irq from non-DP
 	 * the non-DP HPD could block the workqueue on a mode config
diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
index c1d8c23baa39..a4596be4d34a 100644
--- a/drivers/usb/typec/altmodes/displayport.c
+++ b/drivers/usb/typec/altmodes/displayport.c
@@ -59,7 +59,6 @@ struct dp_altmode {
 	struct typec_displayport_data data;
 
 	enum dp_state state;
-	bool hpd;
 
 	struct mutex lock; /* device lock */
 	struct work_struct work;
@@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
 		if (!ret)
 			dp->state = DP_STATE_CONFIGURE;
 	} else {
-		if (dp->hpd != hpd) {
-			drm_connector_oob_hotplug_event(dp->connector_fwnode);
-			dp->hpd = hpd;
-		}
+		drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
 	}
 
 	return ret;
@@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
 	cancel_work_sync(&dp->work);
 
 	if (dp->connector_fwnode) {
-		if (dp->hpd)
-			drm_connector_oob_hotplug_event(dp->connector_fwnode);
+		drm_connector_oob_hotplug_event(dp->connector_fwnode, false);
 
 		fwnode_handle_put(dp->connector_fwnode);
 	}
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 64cf5f88c05b..7c90b8eb2ace 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -1141,7 +1141,7 @@ struct drm_connector_funcs {
 	 * This will get called when a hotplug-event for a drm-connector
 	 * has been received from a source outside the display driver / device.
 	 */
-	void (*oob_hotplug_event)(struct drm_connector *connector);
+	void (*oob_hotplug_event)(struct drm_connector *connector, bool hpd_state);
 };
 
 /**
@@ -1742,7 +1742,8 @@ drm_connector_is_unregistered(struct drm_connector *connector)
 		DRM_CONNECTOR_UNREGISTERED;
 }
 
-void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode);
+void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
+				     bool hpd_state);
 const char *drm_get_connector_type_name(unsigned int connector_type);
 const char *drm_get_connector_status_name(enum drm_connector_status status);
 const char *drm_get_subpixel_order_name(enum subpixel_order order);
-- 
2.33.1

[PATCH 2/2] drm/msm/dp: Implement oob_hotplug_event()

[Bjorn Andersson]

The Qualcomm DisplayPort driver contains traces of the necessary
plumbing to hook up USB HPD, in the form of the dp_hpd module and the
dp_usbpd_cb struct. Use this as basis for implementing the
oob_hotplug_event() callback, by amending the dp_hpd module with the
missing logic.

Overall the solution is similar to what's done downstream, but upstream
all the code to disect the HPD notification lives on the calling side of
drm_connector_oob_hotplug_event().

drm_connector_oob_hotplug_event() performs the lookup of the
drm_connector based on fwnode, hence the need to assign the fwnode in
dp_drm_connector_init().

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
 drivers/gpu/drm/msm/dp/dp_display.c |  8 ++++++++
 drivers/gpu/drm/msm/dp/dp_display.h |  2 ++
 drivers/gpu/drm/msm/dp/dp_drm.c     | 10 ++++++++++
 drivers/gpu/drm/msm/dp/dp_hpd.c     | 19 +++++++++++++++++++
 drivers/gpu/drm/msm/dp/dp_hpd.h     |  4 ++++
 5 files changed, 43 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 7cc4d21f2091..124a2f794382 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -414,6 +414,13 @@ static int dp_display_usbpd_configure_cb(struct device *dev)
 	return dp_display_process_hpd_high(dp);
 }
 
+void dp_display_oob_hotplug_event(struct msm_dp *dp_display, bool hpd_state)
+{
+	struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);
+
+	dp->usbpd->oob_event(dp->usbpd, hpd_state);
+}
+
 static int dp_display_usbpd_disconnect_cb(struct device *dev)
 {
 	struct dp_display_private *dp = dev_get_dp_display_private(dev);
@@ -1251,6 +1258,7 @@ static int dp_display_probe(struct platform_device *pdev)
 	dp->pdev = pdev;
 	dp->name = "drm_dp";
 	dp->dp_display.connector_type = desc->connector_type;
+	dp->dp_display.dev = &pdev->dev;
 
 	rc = dp_init_sub_modules(dp);
 	if (rc) {
diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
index e3adcd578a90..1f856b3bca79 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.h
+++ b/drivers/gpu/drm/msm/dp/dp_display.h
@@ -11,6 +11,7 @@
 #include "disp/msm_disp_snapshot.h"
 
 struct msm_dp {
+	struct device *dev;
 	struct drm_device *drm_dev;
 	struct device *codec_dev;
 	struct drm_bridge *bridge;
@@ -40,5 +41,6 @@ bool dp_display_check_video_test(struct msm_dp *dp_display);
 int dp_display_get_test_bpp(struct msm_dp *dp_display);
 void dp_display_signal_audio_start(struct msm_dp *dp_display);
 void dp_display_signal_audio_complete(struct msm_dp *dp_display);
+void dp_display_oob_hotplug_event(struct msm_dp *dp_display, bool hpd_state);
 
 #endif /* _DP_DISPLAY_H_ */
diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c
index d4d360d19eba..665568197c49 100644
--- a/drivers/gpu/drm/msm/dp/dp_drm.c
+++ b/drivers/gpu/drm/msm/dp/dp_drm.c
@@ -123,6 +123,13 @@ static enum drm_mode_status dp_connector_mode_valid(
 	return dp_display_validate_mode(dp_disp, mode->clock);
 }
 
+static void dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
+{
+	struct msm_dp *dp_disp = to_dp_connector(connector)->dp_display;
+
+	dp_display_oob_hotplug_event(dp_disp, hpd_state);
+}
+
 static const struct drm_connector_funcs dp_connector_funcs = {
 	.detect = dp_connector_detect,
 	.fill_modes = drm_helper_probe_single_connector_modes,
@@ -130,6 +137,7 @@ static const struct drm_connector_funcs dp_connector_funcs = {
 	.reset = drm_atomic_helper_connector_reset,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+	.oob_hotplug_event = dp_oob_hotplug_event,
 };
 
 static const struct drm_connector_helper_funcs dp_connector_helper_funcs = {
@@ -160,6 +168,8 @@ struct drm_connector *dp_drm_connector_init(struct msm_dp *dp_display)
 	if (ret)
 		return ERR_PTR(ret);
 
+	connector->fwnode = fwnode_handle_get(dev_fwnode(dp_display->dev));
+
 	drm_connector_helper_add(connector, &dp_connector_helper_funcs);
 
 	/*
diff --git a/drivers/gpu/drm/msm/dp/dp_hpd.c b/drivers/gpu/drm/msm/dp/dp_hpd.c
index db98a1d431eb..3e62852a18b4 100644
--- a/drivers/gpu/drm/msm/dp/dp_hpd.c
+++ b/drivers/gpu/drm/msm/dp/dp_hpd.c
@@ -7,6 +7,7 @@
 
 #include <linux/slab.h>
 #include <linux/device.h>
+#include <drm/drm_print.h>
 
 #include "dp_hpd.h"
 
@@ -45,6 +46,23 @@ int dp_hpd_connect(struct dp_usbpd *dp_usbpd, bool hpd)
 	return rc;
 }
 
+static void dp_hpd_oob_event(struct dp_usbpd *dp_usbpd, bool hpd_state)
+{
+	struct dp_hpd_private *hpd_priv = container_of(dp_usbpd, struct dp_hpd_private, dp_usbpd);
+
+	DRM_DEBUG_DP("hpd_state: %d connected: %d\n", hpd_state, dp_usbpd->connected);
+
+	if (!dp_usbpd->connected && hpd_state) {
+		dp_usbpd->connected = true;
+		hpd_priv->dp_cb->configure(hpd_priv->dev);
+	} else if (!hpd_state) {
+		dp_usbpd->connected = false;
+		hpd_priv->dp_cb->disconnect(hpd_priv->dev);
+	} else {
+		hpd_priv->dp_cb->attention(hpd_priv->dev);
+	}
+}
+
 struct dp_usbpd *dp_hpd_get(struct device *dev, struct dp_usbpd_cb *cb)
 {
 	struct dp_hpd_private *dp_hpd;
@@ -62,6 +80,7 @@ struct dp_usbpd *dp_hpd_get(struct device *dev, struct dp_usbpd_cb *cb)
 	dp_hpd->dp_cb = cb;
 
 	dp_hpd->dp_usbpd.connect = dp_hpd_connect;
+	dp_hpd->dp_usbpd.oob_event = dp_hpd_oob_event;
 
 	return &dp_hpd->dp_usbpd;
 }
diff --git a/drivers/gpu/drm/msm/dp/dp_hpd.h b/drivers/gpu/drm/msm/dp/dp_hpd.h
index 8feec5aa5027..310ecc2a8538 100644
--- a/drivers/gpu/drm/msm/dp/dp_hpd.h
+++ b/drivers/gpu/drm/msm/dp/dp_hpd.h
@@ -29,7 +29,9 @@ enum plug_orientation {
  * @hpd_irq: Change in the status since last message
  * @alt_mode_cfg_done: bool to specify alt mode status
  * @debug_en: bool to specify debug mode
+ * @connected: cable currently connected
  * @connect: simulate disconnect or connect for debug mode
+ * @oob_event: deliver oob event to the usbpd code
  */
 struct dp_usbpd {
 	enum plug_orientation orientation;
@@ -41,8 +43,10 @@ struct dp_usbpd {
 	bool hpd_irq;
 	bool alt_mode_cfg_done;
 	bool debug_en;
+	bool connected;
 
 	int (*connect)(struct dp_usbpd *dp_usbpd, bool hpd);
+	void (*oob_event)(struct dp_usbpd *dp_usbpd, bool hpd_state);
 };
 
 /**
-- 
2.33.1

[PATCH 2/2] drm/msm/dp: Implement oob_hotplug_event()

[Bjorn Andersson]

The Qualcomm DisplayPort driver contains traces of the necessary
plumbing to hook up USB HPD, in the form of the dp_hpd module and the
dp_usbpd_cb struct. Use this as basis for implementing the
oob_hotplug_event() callback, by amending the dp_hpd module with the
missing logic.

Overall the solution is similar to what's done downstream, but upstream
all the code to disect the HPD notification lives on the calling side of
drm_connector_oob_hotplug_event().

drm_connector_oob_hotplug_event() performs the lookup of the
drm_connector based on fwnode, hence the need to assign the fwnode in
dp_drm_connector_init().

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
 drivers/gpu/drm/msm/dp/dp_display.c |  8 ++++++++
 drivers/gpu/drm/msm/dp/dp_display.h |  2 ++
 drivers/gpu/drm/msm/dp/dp_drm.c     | 10 ++++++++++
 drivers/gpu/drm/msm/dp/dp_hpd.c     | 19 +++++++++++++++++++
 drivers/gpu/drm/msm/dp/dp_hpd.h     |  4 ++++
 5 files changed, 43 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 7cc4d21f2091..124a2f794382 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -414,6 +414,13 @@ static int dp_display_usbpd_configure_cb(struct device *dev)
 	return dp_display_process_hpd_high(dp);
 }
 
+void dp_display_oob_hotplug_event(struct msm_dp *dp_display, bool hpd_state)
+{
+	struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);
+
+	dp->usbpd->oob_event(dp->usbpd, hpd_state);
+}
+
 static int dp_display_usbpd_disconnect_cb(struct device *dev)
 {
 	struct dp_display_private *dp = dev_get_dp_display_private(dev);
@@ -1251,6 +1258,7 @@ static int dp_display_probe(struct platform_device *pdev)
 	dp->pdev = pdev;
 	dp->name = "drm_dp";
 	dp->dp_display.connector_type = desc->connector_type;
+	dp->dp_display.dev = &pdev->dev;
 
 	rc = dp_init_sub_modules(dp);
 	if (rc) {
diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
index e3adcd578a90..1f856b3bca79 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.h
+++ b/drivers/gpu/drm/msm/dp/dp_display.h
@@ -11,6 +11,7 @@
 #include "disp/msm_disp_snapshot.h"
 
 struct msm_dp {
+	struct device *dev;
 	struct drm_device *drm_dev;
 	struct device *codec_dev;
 	struct drm_bridge *bridge;
@@ -40,5 +41,6 @@ bool dp_display_check_video_test(struct msm_dp *dp_display);
 int dp_display_get_test_bpp(struct msm_dp *dp_display);
 void dp_display_signal_audio_start(struct msm_dp *dp_display);
 void dp_display_signal_audio_complete(struct msm_dp *dp_display);
+void dp_display_oob_hotplug_event(struct msm_dp *dp_display, bool hpd_state);
 
 #endif /* _DP_DISPLAY_H_ */
diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c
index d4d360d19eba..665568197c49 100644
--- a/drivers/gpu/drm/msm/dp/dp_drm.c
+++ b/drivers/gpu/drm/msm/dp/dp_drm.c
@@ -123,6 +123,13 @@ static enum drm_mode_status dp_connector_mode_valid(
 	return dp_display_validate_mode(dp_disp, mode->clock);
 }
 
+static void dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
+{
+	struct msm_dp *dp_disp = to_dp_connector(connector)->dp_display;
+
+	dp_display_oob_hotplug_event(dp_disp, hpd_state);
+}
+
 static const struct drm_connector_funcs dp_connector_funcs = {
 	.detect = dp_connector_detect,
 	.fill_modes = drm_helper_probe_single_connector_modes,
@@ -130,6 +137,7 @@ static const struct drm_connector_funcs dp_connector_funcs = {
 	.reset = drm_atomic_helper_connector_reset,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+	.oob_hotplug_event = dp_oob_hotplug_event,
 };
 
 static const struct drm_connector_helper_funcs dp_connector_helper_funcs = {
@@ -160,6 +168,8 @@ struct drm_connector *dp_drm_connector_init(struct msm_dp *dp_display)
 	if (ret)
 		return ERR_PTR(ret);
 
+	connector->fwnode = fwnode_handle_get(dev_fwnode(dp_display->dev));
+
 	drm_connector_helper_add(connector, &dp_connector_helper_funcs);
 
 	/*
diff --git a/drivers/gpu/drm/msm/dp/dp_hpd.c b/drivers/gpu/drm/msm/dp/dp_hpd.c
index db98a1d431eb..3e62852a18b4 100644
--- a/drivers/gpu/drm/msm/dp/dp_hpd.c
+++ b/drivers/gpu/drm/msm/dp/dp_hpd.c
@@ -7,6 +7,7 @@
 
 #include <linux/slab.h>
 #include <linux/device.h>
+#include <drm/drm_print.h>
 
 #include "dp_hpd.h"
 
@@ -45,6 +46,23 @@ int dp_hpd_connect(struct dp_usbpd *dp_usbpd, bool hpd)
 	return rc;
 }
 
+static void dp_hpd_oob_event(struct dp_usbpd *dp_usbpd, bool hpd_state)
+{
+	struct dp_hpd_private *hpd_priv = container_of(dp_usbpd, struct dp_hpd_private, dp_usbpd);
+
+	DRM_DEBUG_DP("hpd_state: %d connected: %d\n", hpd_state, dp_usbpd->connected);
+
+	if (!dp_usbpd->connected && hpd_state) {
+		dp_usbpd->connected = true;
+		hpd_priv->dp_cb->configure(hpd_priv->dev);
+	} else if (!hpd_state) {
+		dp_usbpd->connected = false;
+		hpd_priv->dp_cb->disconnect(hpd_priv->dev);
+	} else {
+		hpd_priv->dp_cb->attention(hpd_priv->dev);
+	}
+}
+
 struct dp_usbpd *dp_hpd_get(struct device *dev, struct dp_usbpd_cb *cb)
 {
 	struct dp_hpd_private *dp_hpd;
@@ -62,6 +80,7 @@ struct dp_usbpd *dp_hpd_get(struct device *dev, struct dp_usbpd_cb *cb)
 	dp_hpd->dp_cb = cb;
 
 	dp_hpd->dp_usbpd.connect = dp_hpd_connect;
+	dp_hpd->dp_usbpd.oob_event = dp_hpd_oob_event;
 
 	return &dp_hpd->dp_usbpd;
 }
diff --git a/drivers/gpu/drm/msm/dp/dp_hpd.h b/drivers/gpu/drm/msm/dp/dp_hpd.h
index 8feec5aa5027..310ecc2a8538 100644
--- a/drivers/gpu/drm/msm/dp/dp_hpd.h
+++ b/drivers/gpu/drm/msm/dp/dp_hpd.h
@@ -29,7 +29,9 @@ enum plug_orientation {
  * @hpd_irq: Change in the status since last message
  * @alt_mode_cfg_done: bool to specify alt mode status
  * @debug_en: bool to specify debug mode
+ * @connected: cable currently connected
  * @connect: simulate disconnect or connect for debug mode
+ * @oob_event: deliver oob event to the usbpd code
  */
 struct dp_usbpd {
 	enum plug_orientation orientation;
@@ -41,8 +43,10 @@ struct dp_usbpd {
 	bool hpd_irq;
 	bool alt_mode_cfg_done;
 	bool debug_en;
+	bool connected;
 
 	int (*connect)(struct dp_usbpd *dp_usbpd, bool hpd);
+	void (*oob_event)(struct dp_usbpd *dp_usbpd, bool hpd_state);
 };
 
 /**
-- 
2.33.1

[Intel-gfx] [PATCH 2/2] drm/msm/dp: Implement oob_hotplug_event()

[Bjorn Andersson]

The Qualcomm DisplayPort driver contains traces of the necessary
plumbing to hook up USB HPD, in the form of the dp_hpd module and the
dp_usbpd_cb struct. Use this as basis for implementing the
oob_hotplug_event() callback, by amending the dp_hpd module with the
missing logic.

Overall the solution is similar to what's done downstream, but upstream
all the code to disect the HPD notification lives on the calling side of
drm_connector_oob_hotplug_event().

drm_connector_oob_hotplug_event() performs the lookup of the
drm_connector based on fwnode, hence the need to assign the fwnode in
dp_drm_connector_init().

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
 drivers/gpu/drm/msm/dp/dp_display.c |  8 ++++++++
 drivers/gpu/drm/msm/dp/dp_display.h |  2 ++
 drivers/gpu/drm/msm/dp/dp_drm.c     | 10 ++++++++++
 drivers/gpu/drm/msm/dp/dp_hpd.c     | 19 +++++++++++++++++++
 drivers/gpu/drm/msm/dp/dp_hpd.h     |  4 ++++
 5 files changed, 43 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 7cc4d21f2091..124a2f794382 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -414,6 +414,13 @@ static int dp_display_usbpd_configure_cb(struct device *dev)
 	return dp_display_process_hpd_high(dp);
 }
 
+void dp_display_oob_hotplug_event(struct msm_dp *dp_display, bool hpd_state)
+{
+	struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);
+
+	dp->usbpd->oob_event(dp->usbpd, hpd_state);
+}
+
 static int dp_display_usbpd_disconnect_cb(struct device *dev)
 {
 	struct dp_display_private *dp = dev_get_dp_display_private(dev);
@@ -1251,6 +1258,7 @@ static int dp_display_probe(struct platform_device *pdev)
 	dp->pdev = pdev;
 	dp->name = "drm_dp";
 	dp->dp_display.connector_type = desc->connector_type;
+	dp->dp_display.dev = &pdev->dev;
 
 	rc = dp_init_sub_modules(dp);
 	if (rc) {
diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
index e3adcd578a90..1f856b3bca79 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.h
+++ b/drivers/gpu/drm/msm/dp/dp_display.h
@@ -11,6 +11,7 @@
 #include "disp/msm_disp_snapshot.h"
 
 struct msm_dp {
+	struct device *dev;
 	struct drm_device *drm_dev;
 	struct device *codec_dev;
 	struct drm_bridge *bridge;
@@ -40,5 +41,6 @@ bool dp_display_check_video_test(struct msm_dp *dp_display);
 int dp_display_get_test_bpp(struct msm_dp *dp_display);
 void dp_display_signal_audio_start(struct msm_dp *dp_display);
 void dp_display_signal_audio_complete(struct msm_dp *dp_display);
+void dp_display_oob_hotplug_event(struct msm_dp *dp_display, bool hpd_state);
 
 #endif /* _DP_DISPLAY_H_ */
diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c
index d4d360d19eba..665568197c49 100644
--- a/drivers/gpu/drm/msm/dp/dp_drm.c
+++ b/drivers/gpu/drm/msm/dp/dp_drm.c
@@ -123,6 +123,13 @@ static enum drm_mode_status dp_connector_mode_valid(
 	return dp_display_validate_mode(dp_disp, mode->clock);
 }
 
+static void dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
+{
+	struct msm_dp *dp_disp = to_dp_connector(connector)->dp_display;
+
+	dp_display_oob_hotplug_event(dp_disp, hpd_state);
+}
+
 static const struct drm_connector_funcs dp_connector_funcs = {
 	.detect = dp_connector_detect,
 	.fill_modes = drm_helper_probe_single_connector_modes,
@@ -130,6 +137,7 @@ static const struct drm_connector_funcs dp_connector_funcs = {
 	.reset = drm_atomic_helper_connector_reset,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+	.oob_hotplug_event = dp_oob_hotplug_event,
 };
 
 static const struct drm_connector_helper_funcs dp_connector_helper_funcs = {
@@ -160,6 +168,8 @@ struct drm_connector *dp_drm_connector_init(struct msm_dp *dp_display)
 	if (ret)
 		return ERR_PTR(ret);
 
+	connector->fwnode = fwnode_handle_get(dev_fwnode(dp_display->dev));
+
 	drm_connector_helper_add(connector, &dp_connector_helper_funcs);
 
 	/*
diff --git a/drivers/gpu/drm/msm/dp/dp_hpd.c b/drivers/gpu/drm/msm/dp/dp_hpd.c
index db98a1d431eb..3e62852a18b4 100644
--- a/drivers/gpu/drm/msm/dp/dp_hpd.c
+++ b/drivers/gpu/drm/msm/dp/dp_hpd.c
@@ -7,6 +7,7 @@
 
 #include <linux/slab.h>
 #include <linux/device.h>
+#include <drm/drm_print.h>
 
 #include "dp_hpd.h"
 
@@ -45,6 +46,23 @@ int dp_hpd_connect(struct dp_usbpd *dp_usbpd, bool hpd)
 	return rc;
 }
 
+static void dp_hpd_oob_event(struct dp_usbpd *dp_usbpd, bool hpd_state)
+{
+	struct dp_hpd_private *hpd_priv = container_of(dp_usbpd, struct dp_hpd_private, dp_usbpd);
+
+	DRM_DEBUG_DP("hpd_state: %d connected: %d\n", hpd_state, dp_usbpd->connected);
+
+	if (!dp_usbpd->connected && hpd_state) {
+		dp_usbpd->connected = true;
+		hpd_priv->dp_cb->configure(hpd_priv->dev);
+	} else if (!hpd_state) {
+		dp_usbpd->connected = false;
+		hpd_priv->dp_cb->disconnect(hpd_priv->dev);
+	} else {
+		hpd_priv->dp_cb->attention(hpd_priv->dev);
+	}
+}
+
 struct dp_usbpd *dp_hpd_get(struct device *dev, struct dp_usbpd_cb *cb)
 {
 	struct dp_hpd_private *dp_hpd;
@@ -62,6 +80,7 @@ struct dp_usbpd *dp_hpd_get(struct device *dev, struct dp_usbpd_cb *cb)
 	dp_hpd->dp_cb = cb;
 
 	dp_hpd->dp_usbpd.connect = dp_hpd_connect;
+	dp_hpd->dp_usbpd.oob_event = dp_hpd_oob_event;
 
 	return &dp_hpd->dp_usbpd;
 }
diff --git a/drivers/gpu/drm/msm/dp/dp_hpd.h b/drivers/gpu/drm/msm/dp/dp_hpd.h
index 8feec5aa5027..310ecc2a8538 100644
--- a/drivers/gpu/drm/msm/dp/dp_hpd.h
+++ b/drivers/gpu/drm/msm/dp/dp_hpd.h
@@ -29,7 +29,9 @@ enum plug_orientation {
  * @hpd_irq: Change in the status since last message
  * @alt_mode_cfg_done: bool to specify alt mode status
  * @debug_en: bool to specify debug mode
+ * @connected: cable currently connected
  * @connect: simulate disconnect or connect for debug mode
+ * @oob_event: deliver oob event to the usbpd code
  */
 struct dp_usbpd {
 	enum plug_orientation orientation;
@@ -41,8 +43,10 @@ struct dp_usbpd {
 	bool hpd_irq;
 	bool alt_mode_cfg_done;
 	bool debug_en;
+	bool connected;
 
 	int (*connect)(struct dp_usbpd *dp_usbpd, bool hpd);
+	void (*oob_event)(struct dp_usbpd *dp_usbpd, bool hpd_state);
 };
 
 /**
-- 
2.33.1

Re: [PATCH 2/2] drm/msm/dp: Implement oob_hotplug_event()

[Greg Kroah-Hartman]

On Mon, Feb 07, 2022 at 08:43:28PM -0800, Bjorn Andersson wrote:
> The Qualcomm DisplayPort driver contains traces of the necessary
> plumbing to hook up USB HPD, in the form of the dp_hpd module and the
> dp_usbpd_cb struct. Use this as basis for implementing the
> oob_hotplug_event() callback, by amending the dp_hpd module with the
> missing logic.
> 
> Overall the solution is similar to what's done downstream, but upstream
> all the code to disect the HPD notification lives on the calling side of
> drm_connector_oob_hotplug_event().
> 
> drm_connector_oob_hotplug_event() performs the lookup of the
> drm_connector based on fwnode, hence the need to assign the fwnode in
> dp_drm_connector_init().
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
>  drivers/gpu/drm/msm/dp/dp_display.c |  8 ++++++++
>  drivers/gpu/drm/msm/dp/dp_display.h |  2 ++
>  drivers/gpu/drm/msm/dp/dp_drm.c     | 10 ++++++++++
>  drivers/gpu/drm/msm/dp/dp_hpd.c     | 19 +++++++++++++++++++
>  drivers/gpu/drm/msm/dp/dp_hpd.h     |  4 ++++
>  5 files changed, 43 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index 7cc4d21f2091..124a2f794382 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -414,6 +414,13 @@ static int dp_display_usbpd_configure_cb(struct device *dev)
>  	return dp_display_process_hpd_high(dp);
>  }
>  
> +void dp_display_oob_hotplug_event(struct msm_dp *dp_display, bool hpd_state)
> +{
> +	struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);
> +
> +	dp->usbpd->oob_event(dp->usbpd, hpd_state);
> +}
> +
>  static int dp_display_usbpd_disconnect_cb(struct device *dev)
>  {
>  	struct dp_display_private *dp = dev_get_dp_display_private(dev);
> @@ -1251,6 +1258,7 @@ static int dp_display_probe(struct platform_device *pdev)
>  	dp->pdev = pdev;
>  	dp->name = "drm_dp";
>  	dp->dp_display.connector_type = desc->connector_type;
> +	dp->dp_display.dev = &pdev->dev;

You did not properly reference count this pointer you just saved.  What
is to keep that pointer from going away without you knowing about it?

And you already have a pointer to pdev, why save another one here?

>  
>  	rc = dp_init_sub_modules(dp);
>  	if (rc) {
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
> index e3adcd578a90..1f856b3bca79 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.h
> +++ b/drivers/gpu/drm/msm/dp/dp_display.h
> @@ -11,6 +11,7 @@
>  #include "disp/msm_disp_snapshot.h"
>  
>  struct msm_dp {
> +	struct device *dev;
>  	struct drm_device *drm_dev;
>  	struct device *codec_dev;

So you now have pointers to 3 different devices here?  What does 'dev'
point to that the other ones do not?  This needs to be documented really
well here.

thanks,

greg k-h

Re: [PATCH 2/2] drm/msm/dp: Implement oob_hotplug_event()

[Greg Kroah-Hartman]

On Mon, Feb 07, 2022 at 08:43:28PM -0800, Bjorn Andersson wrote:
> The Qualcomm DisplayPort driver contains traces of the necessary
> plumbing to hook up USB HPD, in the form of the dp_hpd module and the
> dp_usbpd_cb struct. Use this as basis for implementing the
> oob_hotplug_event() callback, by amending the dp_hpd module with the
> missing logic.
> 
> Overall the solution is similar to what's done downstream, but upstream
> all the code to disect the HPD notification lives on the calling side of
> drm_connector_oob_hotplug_event().
> 
> drm_connector_oob_hotplug_event() performs the lookup of the
> drm_connector based on fwnode, hence the need to assign the fwnode in
> dp_drm_connector_init().
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
>  drivers/gpu/drm/msm/dp/dp_display.c |  8 ++++++++
>  drivers/gpu/drm/msm/dp/dp_display.h |  2 ++
>  drivers/gpu/drm/msm/dp/dp_drm.c     | 10 ++++++++++
>  drivers/gpu/drm/msm/dp/dp_hpd.c     | 19 +++++++++++++++++++
>  drivers/gpu/drm/msm/dp/dp_hpd.h     |  4 ++++
>  5 files changed, 43 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index 7cc4d21f2091..124a2f794382 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -414,6 +414,13 @@ static int dp_display_usbpd_configure_cb(struct device *dev)
>  	return dp_display_process_hpd_high(dp);
>  }
>  
> +void dp_display_oob_hotplug_event(struct msm_dp *dp_display, bool hpd_state)
> +{
> +	struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);
> +
> +	dp->usbpd->oob_event(dp->usbpd, hpd_state);
> +}
> +
>  static int dp_display_usbpd_disconnect_cb(struct device *dev)
>  {
>  	struct dp_display_private *dp = dev_get_dp_display_private(dev);
> @@ -1251,6 +1258,7 @@ static int dp_display_probe(struct platform_device *pdev)
>  	dp->pdev = pdev;
>  	dp->name = "drm_dp";
>  	dp->dp_display.connector_type = desc->connector_type;
> +	dp->dp_display.dev = &pdev->dev;

You did not properly reference count this pointer you just saved.  What
is to keep that pointer from going away without you knowing about it?

And you already have a pointer to pdev, why save another one here?

>  
>  	rc = dp_init_sub_modules(dp);
>  	if (rc) {
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
> index e3adcd578a90..1f856b3bca79 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.h
> +++ b/drivers/gpu/drm/msm/dp/dp_display.h
> @@ -11,6 +11,7 @@
>  #include "disp/msm_disp_snapshot.h"
>  
>  struct msm_dp {
> +	struct device *dev;
>  	struct drm_device *drm_dev;
>  	struct device *codec_dev;

So you now have pointers to 3 different devices here?  What does 'dev'
point to that the other ones do not?  This needs to be documented really
well here.

thanks,

greg k-h

Re: [Intel-gfx] [PATCH 2/2] drm/msm/dp: Implement oob_hotplug_event()

[Greg Kroah-Hartman]

On Mon, Feb 07, 2022 at 08:43:28PM -0800, Bjorn Andersson wrote:
> The Qualcomm DisplayPort driver contains traces of the necessary
> plumbing to hook up USB HPD, in the form of the dp_hpd module and the
> dp_usbpd_cb struct. Use this as basis for implementing the
> oob_hotplug_event() callback, by amending the dp_hpd module with the
> missing logic.
> 
> Overall the solution is similar to what's done downstream, but upstream
> all the code to disect the HPD notification lives on the calling side of
> drm_connector_oob_hotplug_event().
> 
> drm_connector_oob_hotplug_event() performs the lookup of the
> drm_connector based on fwnode, hence the need to assign the fwnode in
> dp_drm_connector_init().
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
>  drivers/gpu/drm/msm/dp/dp_display.c |  8 ++++++++
>  drivers/gpu/drm/msm/dp/dp_display.h |  2 ++
>  drivers/gpu/drm/msm/dp/dp_drm.c     | 10 ++++++++++
>  drivers/gpu/drm/msm/dp/dp_hpd.c     | 19 +++++++++++++++++++
>  drivers/gpu/drm/msm/dp/dp_hpd.h     |  4 ++++
>  5 files changed, 43 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index 7cc4d21f2091..124a2f794382 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -414,6 +414,13 @@ static int dp_display_usbpd_configure_cb(struct device *dev)
>  	return dp_display_process_hpd_high(dp);
>  }
>  
> +void dp_display_oob_hotplug_event(struct msm_dp *dp_display, bool hpd_state)
> +{
> +	struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);
> +
> +	dp->usbpd->oob_event(dp->usbpd, hpd_state);
> +}
> +
>  static int dp_display_usbpd_disconnect_cb(struct device *dev)
>  {
>  	struct dp_display_private *dp = dev_get_dp_display_private(dev);
> @@ -1251,6 +1258,7 @@ static int dp_display_probe(struct platform_device *pdev)
>  	dp->pdev = pdev;
>  	dp->name = "drm_dp";
>  	dp->dp_display.connector_type = desc->connector_type;
> +	dp->dp_display.dev = &pdev->dev;

You did not properly reference count this pointer you just saved.  What
is to keep that pointer from going away without you knowing about it?

And you already have a pointer to pdev, why save another one here?

>  
>  	rc = dp_init_sub_modules(dp);
>  	if (rc) {
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
> index e3adcd578a90..1f856b3bca79 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.h
> +++ b/drivers/gpu/drm/msm/dp/dp_display.h
> @@ -11,6 +11,7 @@
>  #include "disp/msm_disp_snapshot.h"
>  
>  struct msm_dp {
> +	struct device *dev;
>  	struct drm_device *drm_dev;
>  	struct device *codec_dev;

So you now have pointers to 3 different devices here?  What does 'dev'
point to that the other ones do not?  This needs to be documented really
well here.

thanks,

greg k-h

[Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for series starting with [1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Patchwork]

== Series Details ==

Series: series starting with [1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()
URL   : https://patchwork.freedesktop.org/series/99830/
State : warning

== Summary ==

$ dim checkpatch origin/drm-tip
74980bd036b7 drm: Add HPD state to drm_connector_oob_hotplug_event()
8b5650e44ccf drm/msm/dp: Implement oob_hotplug_event()
-:32: WARNING:LONG_LINE: line length of 104 exceeds 100 columns
#32: FILE: drivers/gpu/drm/msm/dp/dp_display.c:419:
+	struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);

total: 0 errors, 1 warnings, 0 checks, 117 lines checked

[Intel-gfx] ✗ Fi.CI.SPARSE: warning for series starting with [1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Patchwork]

== Series Details ==

Series: series starting with [1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()
URL   : https://patchwork.freedesktop.org/series/99830/
State : warning

== Summary ==

$ dim sparse --fast origin/drm-tip
Sparse version: v0.6.2
Fast mode used, each commit won't be checked separately.

Re: [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Greg Kroah-Hartman]

On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> In some implementations, such as the Qualcomm platforms, the display
> driver has no way to query the current HPD state and as such it's
> impossible to distinguish between disconnect and attention events.
> 
> Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> state.
> 
> Also push the test for unchanged state in the displayport altmode driver
> into the i915 driver, to allow other drivers to act upon each update.
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
> 
> Note that the Intel driver has only been compile tested with this patch.
> 
>  drivers/gpu/drm/drm_connector.c          |  6 ++++--
>  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
>  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
>  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
>  include/drm/drm_connector.h              |  5 +++--
>  5 files changed, 23 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index a50c82bc2b2f..ad7295597c0f 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
>  /**
>   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
>   * @connector_fwnode: fwnode_handle to report the event on
> + * @hpd_state: number of data lanes available

"number"?

>   *
>   * On some hardware a hotplug event notification may come from outside the display
>   * driver / device. An example of this is some USB Type-C setups where the hardware
> @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
>   * This function can be used to report these out-of-band events after obtaining
>   * a drm_connector reference through calling drm_connector_find_by_fwnode().
>   */
> -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> +				     bool hpd_state)

This is a boolean, how can it be a number?

And having a "flag" like this is a pain, how do you know what the
parameter really means?

>  {
>  	struct drm_connector *connector;
>  
> @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
>  		return;
>  
>  	if (connector->funcs->oob_hotplug_event)
> -		connector->funcs->oob_hotplug_event(connector);
> +		connector->funcs->oob_hotplug_event(connector, hpd_state);
>  
>  	drm_connector_put(connector);
>  }
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 146b83916005..00520867d37b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
>  	return intel_modeset_synced_crtcs(state, conn);
>  }
>  
> -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
>  {
>  	struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
>  	struct drm_i915_private *i915 = to_i915(connector->dev);
> +	bool need_work = false;
>  
>  	spin_lock_irq(&i915->irq_lock);
> -	i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> +	if (hpd_state != i915->hotplug.oob_hotplug_state) {
> +		i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> +
> +		i915->hotplug.oob_hotplug_state = hpd_state;
> +		need_work = true;
> +	}
>  	spin_unlock_irq(&i915->irq_lock);
> -	queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> +
> +	if (need_work)
> +		queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
>  }
>  
>  static const struct drm_connector_funcs intel_dp_connector_funcs = {
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 8c1706fd81f9..543ebf1cfcf4 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -149,6 +149,9 @@ struct i915_hotplug {
>  	/* Whether or not to count short HPD IRQs in HPD storms */
>  	u8 hpd_short_storm_enabled;
>  
> +	/* Last state reported by oob_hotplug_event */
> +	bool oob_hotplug_state;
> +
>  	/*
>  	 * if we get a HPD irq from DP and a HPD irq from non-DP
>  	 * the non-DP HPD could block the workqueue on a mode config
> diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> index c1d8c23baa39..a4596be4d34a 100644
> --- a/drivers/usb/typec/altmodes/displayport.c
> +++ b/drivers/usb/typec/altmodes/displayport.c
> @@ -59,7 +59,6 @@ struct dp_altmode {
>  	struct typec_displayport_data data;
>  
>  	enum dp_state state;
> -	bool hpd;
>  
>  	struct mutex lock; /* device lock */
>  	struct work_struct work;
> @@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
>  		if (!ret)
>  			dp->state = DP_STATE_CONFIGURE;
>  	} else {
> -		if (dp->hpd != hpd) {
> -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> -			dp->hpd = hpd;
> -		}
> +		drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
>  	}
>  
>  	return ret;
> @@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
>  	cancel_work_sync(&dp->work);
>  
>  	if (dp->connector_fwnode) {
> -		if (dp->hpd)
> -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> +		drm_connector_oob_hotplug_event(dp->connector_fwnode, false);

See, what does "false" here mean?

Name the function for what it does, do not have random flags as
parameters, that makes it impossible to understand what the code is
doing when you are reading it, without having to jump around and figure
out what the flags are saying.

And here they just don't even seem to be right :(

thanks,

greg k-h

Re: [Intel-gfx] [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Greg Kroah-Hartman]

On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> In some implementations, such as the Qualcomm platforms, the display
> driver has no way to query the current HPD state and as such it's
> impossible to distinguish between disconnect and attention events.
> 
> Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> state.
> 
> Also push the test for unchanged state in the displayport altmode driver
> into the i915 driver, to allow other drivers to act upon each update.
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
> 
> Note that the Intel driver has only been compile tested with this patch.
> 
>  drivers/gpu/drm/drm_connector.c          |  6 ++++--
>  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
>  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
>  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
>  include/drm/drm_connector.h              |  5 +++--
>  5 files changed, 23 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index a50c82bc2b2f..ad7295597c0f 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
>  /**
>   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
>   * @connector_fwnode: fwnode_handle to report the event on
> + * @hpd_state: number of data lanes available

"number"?

>   *
>   * On some hardware a hotplug event notification may come from outside the display
>   * driver / device. An example of this is some USB Type-C setups where the hardware
> @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
>   * This function can be used to report these out-of-band events after obtaining
>   * a drm_connector reference through calling drm_connector_find_by_fwnode().
>   */
> -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> +				     bool hpd_state)

This is a boolean, how can it be a number?

And having a "flag" like this is a pain, how do you know what the
parameter really means?

>  {
>  	struct drm_connector *connector;
>  
> @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
>  		return;
>  
>  	if (connector->funcs->oob_hotplug_event)
> -		connector->funcs->oob_hotplug_event(connector);
> +		connector->funcs->oob_hotplug_event(connector, hpd_state);
>  
>  	drm_connector_put(connector);
>  }
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 146b83916005..00520867d37b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
>  	return intel_modeset_synced_crtcs(state, conn);
>  }
>  
> -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
>  {
>  	struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
>  	struct drm_i915_private *i915 = to_i915(connector->dev);
> +	bool need_work = false;
>  
>  	spin_lock_irq(&i915->irq_lock);
> -	i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> +	if (hpd_state != i915->hotplug.oob_hotplug_state) {
> +		i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> +
> +		i915->hotplug.oob_hotplug_state = hpd_state;
> +		need_work = true;
> +	}
>  	spin_unlock_irq(&i915->irq_lock);
> -	queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> +
> +	if (need_work)
> +		queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
>  }
>  
>  static const struct drm_connector_funcs intel_dp_connector_funcs = {
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 8c1706fd81f9..543ebf1cfcf4 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -149,6 +149,9 @@ struct i915_hotplug {
>  	/* Whether or not to count short HPD IRQs in HPD storms */
>  	u8 hpd_short_storm_enabled;
>  
> +	/* Last state reported by oob_hotplug_event */
> +	bool oob_hotplug_state;
> +
>  	/*
>  	 * if we get a HPD irq from DP and a HPD irq from non-DP
>  	 * the non-DP HPD could block the workqueue on a mode config
> diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> index c1d8c23baa39..a4596be4d34a 100644
> --- a/drivers/usb/typec/altmodes/displayport.c
> +++ b/drivers/usb/typec/altmodes/displayport.c
> @@ -59,7 +59,6 @@ struct dp_altmode {
>  	struct typec_displayport_data data;
>  
>  	enum dp_state state;
> -	bool hpd;
>  
>  	struct mutex lock; /* device lock */
>  	struct work_struct work;
> @@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
>  		if (!ret)
>  			dp->state = DP_STATE_CONFIGURE;
>  	} else {
> -		if (dp->hpd != hpd) {
> -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> -			dp->hpd = hpd;
> -		}
> +		drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
>  	}
>  
>  	return ret;
> @@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
>  	cancel_work_sync(&dp->work);
>  
>  	if (dp->connector_fwnode) {
> -		if (dp->hpd)
> -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> +		drm_connector_oob_hotplug_event(dp->connector_fwnode, false);

See, what does "false" here mean?

Name the function for what it does, do not have random flags as
parameters, that makes it impossible to understand what the code is
doing when you are reading it, without having to jump around and figure
out what the flags are saying.

And here they just don't even seem to be right :(

thanks,

greg k-h

Re: [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Greg Kroah-Hartman]

On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> In some implementations, such as the Qualcomm platforms, the display
> driver has no way to query the current HPD state and as such it's
> impossible to distinguish between disconnect and attention events.
> 
> Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> state.
> 
> Also push the test for unchanged state in the displayport altmode driver
> into the i915 driver, to allow other drivers to act upon each update.
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
> 
> Note that the Intel driver has only been compile tested with this patch.
> 
>  drivers/gpu/drm/drm_connector.c          |  6 ++++--
>  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
>  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
>  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
>  include/drm/drm_connector.h              |  5 +++--
>  5 files changed, 23 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index a50c82bc2b2f..ad7295597c0f 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
>  /**
>   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
>   * @connector_fwnode: fwnode_handle to report the event on
> + * @hpd_state: number of data lanes available

"number"?

>   *
>   * On some hardware a hotplug event notification may come from outside the display
>   * driver / device. An example of this is some USB Type-C setups where the hardware
> @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
>   * This function can be used to report these out-of-band events after obtaining
>   * a drm_connector reference through calling drm_connector_find_by_fwnode().
>   */
> -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> +				     bool hpd_state)

This is a boolean, how can it be a number?

And having a "flag" like this is a pain, how do you know what the
parameter really means?

>  {
>  	struct drm_connector *connector;
>  
> @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
>  		return;
>  
>  	if (connector->funcs->oob_hotplug_event)
> -		connector->funcs->oob_hotplug_event(connector);
> +		connector->funcs->oob_hotplug_event(connector, hpd_state);
>  
>  	drm_connector_put(connector);
>  }
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 146b83916005..00520867d37b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
>  	return intel_modeset_synced_crtcs(state, conn);
>  }
>  
> -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
>  {
>  	struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
>  	struct drm_i915_private *i915 = to_i915(connector->dev);
> +	bool need_work = false;
>  
>  	spin_lock_irq(&i915->irq_lock);
> -	i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> +	if (hpd_state != i915->hotplug.oob_hotplug_state) {
> +		i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> +
> +		i915->hotplug.oob_hotplug_state = hpd_state;
> +		need_work = true;
> +	}
>  	spin_unlock_irq(&i915->irq_lock);
> -	queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> +
> +	if (need_work)
> +		queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
>  }
>  
>  static const struct drm_connector_funcs intel_dp_connector_funcs = {
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 8c1706fd81f9..543ebf1cfcf4 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -149,6 +149,9 @@ struct i915_hotplug {
>  	/* Whether or not to count short HPD IRQs in HPD storms */
>  	u8 hpd_short_storm_enabled;
>  
> +	/* Last state reported by oob_hotplug_event */
> +	bool oob_hotplug_state;
> +
>  	/*
>  	 * if we get a HPD irq from DP and a HPD irq from non-DP
>  	 * the non-DP HPD could block the workqueue on a mode config
> diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> index c1d8c23baa39..a4596be4d34a 100644
> --- a/drivers/usb/typec/altmodes/displayport.c
> +++ b/drivers/usb/typec/altmodes/displayport.c
> @@ -59,7 +59,6 @@ struct dp_altmode {
>  	struct typec_displayport_data data;
>  
>  	enum dp_state state;
> -	bool hpd;
>  
>  	struct mutex lock; /* device lock */
>  	struct work_struct work;
> @@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
>  		if (!ret)
>  			dp->state = DP_STATE_CONFIGURE;
>  	} else {
> -		if (dp->hpd != hpd) {
> -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> -			dp->hpd = hpd;
> -		}
> +		drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
>  	}
>  
>  	return ret;
> @@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
>  	cancel_work_sync(&dp->work);
>  
>  	if (dp->connector_fwnode) {
> -		if (dp->hpd)
> -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> +		drm_connector_oob_hotplug_event(dp->connector_fwnode, false);

See, what does "false" here mean?

Name the function for what it does, do not have random flags as
parameters, that makes it impossible to understand what the code is
doing when you are reading it, without having to jump around and figure
out what the flags are saying.

And here they just don't even seem to be right :(

thanks,

greg k-h

[Intel-gfx] ✗ Fi.CI.BAT: failure for series starting with [1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Patchwork]

[-- Attachment #1: Type: text/plain, Size: 12957 bytes --]

== Series Details ==

Series: series starting with [1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()
URL   : https://patchwork.freedesktop.org/series/99830/
State : failure

== Summary ==

CI Bug Log - changes from CI_DRM_11200 -> Patchwork_22200
====================================================

Summary
-------

  **FAILURE**

  Serious unknown changes coming with Patchwork_22200 absolutely need to be
  verified manually.
  
  If you think the reported changes have nothing to do with the changes
  introduced in Patchwork_22200, please notify your bug team to allow them
  to document this new failure mode, which will reduce false positives in CI.

  External URL: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/index.html

Participating hosts (42 -> 43)
------------------------------

  Additional (4): fi-kbl-soraka bat-jsl-2 fi-icl-u2 bat-dg1-5 
  Missing    (3): shard-rkl shard-tglu fi-tgl-dsi 

Possible new issues
-------------------

  Here are the unknown changes that may have been introduced in Patchwork_22200:

### IGT changes ###

#### Possible regressions ####

  * igt@gem_exec_suspend@basic-s0@smem:
    - fi-kbl-soraka:      NOTRUN -> [INCOMPLETE][1]
   [1]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-kbl-soraka/igt@gem_exec_suspend@basic-s0@smem.html

  
Known issues
------------

  Here are the changes found in Patchwork_22200 that come from known issues:

### IGT changes ###

#### Issues hit ####

  * igt@amdgpu/amd_basic@cs-multi-fence:
    - fi-blb-e6850:       NOTRUN -> [SKIP][2] ([fdo#109271]) +17 similar issues
   [2]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-blb-e6850/igt@amdgpu/amd_basic@cs-multi-fence.html

  * igt@amdgpu/amd_cs_nop@fork-gfx0:
    - fi-icl-u2:          NOTRUN -> [SKIP][3] ([fdo#109315]) +17 similar issues
   [3]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-icl-u2/igt@amdgpu/amd_cs_nop@fork-gfx0.html

  * igt@gem_exec_fence@basic-busy@bcs0:
    - fi-kbl-soraka:      NOTRUN -> [SKIP][4] ([fdo#109271]) +2 similar issues
   [4]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-kbl-soraka/igt@gem_exec_fence@basic-busy@bcs0.html

  * igt@gem_exec_gttfill@basic:
    - bat-dg1-5:          NOTRUN -> [SKIP][5] ([i915#4086])
   [5]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/bat-dg1-5/igt@gem_exec_gttfill@basic.html

  * igt@gem_exec_suspend@basic-s3@smem:
    - fi-bdw-5557u:       [PASS][6] -> [INCOMPLETE][7] ([i915#146])
   [6]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_11200/fi-bdw-5557u/igt@gem_exec_suspend@basic-s3@smem.html
   [7]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-bdw-5557u/igt@gem_exec_suspend@basic-s3@smem.html

  * igt@gem_huc_copy@huc-copy:
    - fi-skl-6600u:       NOTRUN -> [SKIP][8] ([fdo#109271] / [i915#2190])
   [8]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-skl-6600u/igt@gem_huc_copy@huc-copy.html
    - fi-icl-u2:          NOTRUN -> [SKIP][9] ([i915#2190])
   [9]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-icl-u2/igt@gem_huc_copy@huc-copy.html

  * igt@gem_lmem_swapping@parallel-random-engines:
    - fi-icl-u2:          NOTRUN -> [SKIP][10] ([i915#4613]) +3 similar issues
   [10]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-icl-u2/igt@gem_lmem_swapping@parallel-random-engines.html

  * igt@gem_lmem_swapping@verify-random:
    - fi-skl-6600u:       NOTRUN -> [SKIP][11] ([fdo#109271] / [i915#4613]) +3 similar issues
   [11]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-skl-6600u/igt@gem_lmem_swapping@verify-random.html

  * igt@gem_mmap@basic:
    - bat-dg1-5:          NOTRUN -> [SKIP][12] ([i915#4083])
   [12]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/bat-dg1-5/igt@gem_mmap@basic.html

  * igt@gem_tiled_fence_blits@basic:
    - bat-dg1-5:          NOTRUN -> [SKIP][13] ([i915#4077]) +2 similar issues
   [13]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/bat-dg1-5/igt@gem_tiled_fence_blits@basic.html

  * igt@gem_tiled_pread_basic:
    - bat-dg1-5:          NOTRUN -> [SKIP][14] ([i915#4079]) +1 similar issue
   [14]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/bat-dg1-5/igt@gem_tiled_pread_basic.html

  * igt@i915_pm_backlight@basic-brightness:
    - bat-dg1-5:          NOTRUN -> [SKIP][15] ([i915#1155])
   [15]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/bat-dg1-5/igt@i915_pm_backlight@basic-brightness.html

  * igt@i915_selftest@live@hangcheck:
    - bat-dg1-5:          NOTRUN -> [DMESG-FAIL][16] ([i915#4494] / [i915#4957])
   [16]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/bat-dg1-5/igt@i915_selftest@live@hangcheck.html
    - fi-hsw-4770:        [PASS][17] -> [INCOMPLETE][18] ([i915#4785])
   [17]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_11200/fi-hsw-4770/igt@i915_selftest@live@hangcheck.html
   [18]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-hsw-4770/igt@i915_selftest@live@hangcheck.html

  * igt@kms_addfb_basic@basic-y-tiled-legacy:
    - bat-dg1-5:          NOTRUN -> [SKIP][19] ([i915#4215])
   [19]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/bat-dg1-5/igt@kms_addfb_basic@basic-y-tiled-legacy.html

  * igt@kms_addfb_basic@tile-pitch-mismatch:
    - bat-dg1-5:          NOTRUN -> [SKIP][20] ([i915#4212]) +7 similar issues
   [20]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/bat-dg1-5/igt@kms_addfb_basic@tile-pitch-mismatch.html

  * igt@kms_chamelium@hdmi-hpd-fast:
    - fi-icl-u2:          NOTRUN -> [SKIP][21] ([fdo#111827]) +8 similar issues
   [21]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-icl-u2/igt@kms_chamelium@hdmi-hpd-fast.html
    - bat-dg1-5:          NOTRUN -> [SKIP][22] ([fdo#111827]) +8 similar issues
   [22]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/bat-dg1-5/igt@kms_chamelium@hdmi-hpd-fast.html

  * igt@kms_chamelium@vga-edid-read:
    - fi-skl-6600u:       NOTRUN -> [SKIP][23] ([fdo#109271] / [fdo#111827]) +8 similar issues
   [23]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-skl-6600u/igt@kms_chamelium@vga-edid-read.html

  * igt@kms_cursor_legacy@basic-busy-flip-before-cursor-legacy:
    - fi-icl-u2:          NOTRUN -> [SKIP][24] ([fdo#109278]) +2 similar issues
   [24]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-icl-u2/igt@kms_cursor_legacy@basic-busy-flip-before-cursor-legacy.html
    - fi-skl-6600u:       NOTRUN -> [SKIP][25] ([fdo#109271]) +2 similar issues
   [25]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-skl-6600u/igt@kms_cursor_legacy@basic-busy-flip-before-cursor-legacy.html
    - bat-dg1-5:          NOTRUN -> [SKIP][26] ([i915#4103] / [i915#4213]) +1 similar issue
   [26]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/bat-dg1-5/igt@kms_cursor_legacy@basic-busy-flip-before-cursor-legacy.html

  * igt@kms_force_connector_basic@force-load-detect:
    - bat-dg1-5:          NOTRUN -> [SKIP][27] ([fdo#109285])
   [27]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/bat-dg1-5/igt@kms_force_connector_basic@force-load-detect.html
    - fi-icl-u2:          NOTRUN -> [SKIP][28] ([fdo#109285])
   [28]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-icl-u2/igt@kms_force_connector_basic@force-load-detect.html

  * igt@kms_pipe_crc_basic@compare-crc-sanitycheck-pipe-d:
    - fi-skl-6600u:       NOTRUN -> [SKIP][29] ([fdo#109271] / [i915#533])
   [29]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-skl-6600u/igt@kms_pipe_crc_basic@compare-crc-sanitycheck-pipe-d.html

  * igt@kms_psr@primary_page_flip:
    - bat-dg1-5:          NOTRUN -> [SKIP][30] ([i915#1072] / [i915#4078]) +3 similar issues
   [30]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/bat-dg1-5/igt@kms_psr@primary_page_flip.html
    - fi-skl-6600u:       NOTRUN -> [INCOMPLETE][31] ([i915#4838])
   [31]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-skl-6600u/igt@kms_psr@primary_page_flip.html

  * igt@prime_vgem@basic-fence-mmap:
    - bat-dg1-5:          NOTRUN -> [SKIP][32] ([i915#3708] / [i915#4077]) +1 similar issue
   [32]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/bat-dg1-5/igt@prime_vgem@basic-fence-mmap.html

  * igt@prime_vgem@basic-userptr:
    - fi-icl-u2:          NOTRUN -> [SKIP][33] ([i915#3301])
   [33]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-icl-u2/igt@prime_vgem@basic-userptr.html
    - bat-dg1-5:          NOTRUN -> [SKIP][34] ([i915#3708] / [i915#4873])
   [34]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/bat-dg1-5/igt@prime_vgem@basic-userptr.html

  * igt@prime_vgem@basic-write:
    - bat-dg1-5:          NOTRUN -> [SKIP][35] ([i915#3708]) +3 similar issues
   [35]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/bat-dg1-5/igt@prime_vgem@basic-write.html

  * igt@runner@aborted:
    - fi-hsw-4770:        NOTRUN -> [FAIL][36] ([fdo#109271] / [i915#1436] / [i915#4312])
   [36]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-hsw-4770/igt@runner@aborted.html

  
#### Possible fixes ####

  * igt@gem_exec_suspend@basic-s3@smem:
    - fi-skl-6600u:       [INCOMPLETE][37] ([i915#4547]) -> [PASS][38]
   [37]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_11200/fi-skl-6600u/igt@gem_exec_suspend@basic-s3@smem.html
   [38]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-skl-6600u/igt@gem_exec_suspend@basic-s3@smem.html

  * igt@i915_selftest@live@requests:
    - fi-blb-e6850:       [DMESG-FAIL][39] ([i915#4528] / [i915#5026]) -> [PASS][40]
   [39]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_11200/fi-blb-e6850/igt@i915_selftest@live@requests.html
   [40]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/fi-blb-e6850/igt@i915_selftest@live@requests.html

  
  {name}: This element is suppressed. This means it is ignored when computing
          the status of the difference (SUCCESS, WARNING, or FAILURE).

  [fdo#109271]: https://bugs.freedesktop.org/show_bug.cgi?id=109271
  [fdo#109278]: https://bugs.freedesktop.org/show_bug.cgi?id=109278
  [fdo#109285]: https://bugs.freedesktop.org/show_bug.cgi?id=109285
  [fdo#109315]: https://bugs.freedesktop.org/show_bug.cgi?id=109315
  [fdo#111827]: https://bugs.freedesktop.org/show_bug.cgi?id=111827
  [i915#1072]: https://gitlab.freedesktop.org/drm/intel/issues/1072
  [i915#1155]: https://gitlab.freedesktop.org/drm/intel/issues/1155
  [i915#1436]: https://gitlab.freedesktop.org/drm/intel/issues/1436
  [i915#146]: https://gitlab.freedesktop.org/drm/intel/issues/146
  [i915#2190]: https://gitlab.freedesktop.org/drm/intel/issues/2190
  [i915#2582]: https://gitlab.freedesktop.org/drm/intel/issues/2582
  [i915#3301]: https://gitlab.freedesktop.org/drm/intel/issues/3301
  [i915#3708]: https://gitlab.freedesktop.org/drm/intel/issues/3708
  [i915#4077]: https://gitlab.freedesktop.org/drm/intel/issues/4077
  [i915#4078]: https://gitlab.freedesktop.org/drm/intel/issues/4078
  [i915#4079]: https://gitlab.freedesktop.org/drm/intel/issues/4079
  [i915#4083]: https://gitlab.freedesktop.org/drm/intel/issues/4083
  [i915#4086]: https://gitlab.freedesktop.org/drm/intel/issues/4086
  [i915#4103]: https://gitlab.freedesktop.org/drm/intel/issues/4103
  [i915#4212]: https://gitlab.freedesktop.org/drm/intel/issues/4212
  [i915#4213]: https://gitlab.freedesktop.org/drm/intel/issues/4213
  [i915#4215]: https://gitlab.freedesktop.org/drm/intel/issues/4215
  [i915#4312]: https://gitlab.freedesktop.org/drm/intel/issues/4312
  [i915#4494]: https://gitlab.freedesktop.org/drm/intel/issues/4494
  [i915#4528]: https://gitlab.freedesktop.org/drm/intel/issues/4528
  [i915#4547]: https://gitlab.freedesktop.org/drm/intel/issues/4547
  [i915#4613]: https://gitlab.freedesktop.org/drm/intel/issues/4613
  [i915#4785]: https://gitlab.freedesktop.org/drm/intel/issues/4785
  [i915#4838]: https://gitlab.freedesktop.org/drm/intel/issues/4838
  [i915#4873]: https://gitlab.freedesktop.org/drm/intel/issues/4873
  [i915#4898]: https://gitlab.freedesktop.org/drm/intel/issues/4898
  [i915#4957]: https://gitlab.freedesktop.org/drm/intel/issues/4957
  [i915#5026]: https://gitlab.freedesktop.org/drm/intel/issues/5026
  [i915#533]: https://gitlab.freedesktop.org/drm/intel/issues/533


Build changes
-------------

  * Linux: CI_DRM_11200 -> Patchwork_22200

  CI-20190529: 20190529
  CI_DRM_11200: a82048d804ae32de6e00da56d2c74e449d486738 @ git://anongit.freedesktop.org/gfx-ci/linux
  IGT_6341: a96674e747ea2f2431bbf8813156adc44ec3162a @ https://gitlab.freedesktop.org/drm/igt-gpu-tools.git
  Patchwork_22200: 8b5650e44ccfdc98ab0c48ac4b50fe1a4d4a2076 @ git://anongit.freedesktop.org/gfx-ci/linux


== Linux commits ==

8b5650e44ccf drm/msm/dp: Implement oob_hotplug_event()
74980bd036b7 drm: Add HPD state to drm_connector_oob_hotplug_event()

== Logs ==

For more details see: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_22200/index.html

[-- Attachment #2: Type: text/html, Size: 15298 bytes --]

Re: [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Bjorn Andersson]

On Tue 08 Feb 02:39 PST 2022, Greg Kroah-Hartman wrote:

> On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> > In some implementations, such as the Qualcomm platforms, the display
> > driver has no way to query the current HPD state and as such it's
> > impossible to distinguish between disconnect and attention events.
> > 
> > Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> > state.
> > 
> > Also push the test for unchanged state in the displayport altmode driver
> > into the i915 driver, to allow other drivers to act upon each update.
> > 
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > ---
> > 
> > Note that the Intel driver has only been compile tested with this patch.
> > 
> >  drivers/gpu/drm/drm_connector.c          |  6 ++++--
> >  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
> >  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
> >  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
> >  include/drm/drm_connector.h              |  5 +++--
> >  5 files changed, 23 insertions(+), 14 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> > index a50c82bc2b2f..ad7295597c0f 100644
> > --- a/drivers/gpu/drm/drm_connector.c
> > +++ b/drivers/gpu/drm/drm_connector.c
> > @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> >  /**
> >   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
> >   * @connector_fwnode: fwnode_handle to report the event on
> > + * @hpd_state: number of data lanes available
> 
> "number"?
> 
> >   *
> >   * On some hardware a hotplug event notification may come from outside the display
> >   * driver / device. An example of this is some USB Type-C setups where the hardware
> > @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> >   * This function can be used to report these out-of-band events after obtaining
> >   * a drm_connector reference through calling drm_connector_find_by_fwnode().
> >   */
> > -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> > +				     bool hpd_state)
> 
> This is a boolean, how can it be a number?
> 

The kerneldoc wasn't appropriately updated as this went from being
"number of data lanes" to "the hot plug detect (hpd) state".

> And having a "flag" like this is a pain, how do you know what the
> parameter really means?
> 

You're right, "state" isn't a boolean property, let's rename it
"hpd_high" to clarify it.

> >  {
> >  	struct drm_connector *connector;
> >  
> > @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> >  		return;
> >  
> >  	if (connector->funcs->oob_hotplug_event)
> > -		connector->funcs->oob_hotplug_event(connector);
> > +		connector->funcs->oob_hotplug_event(connector, hpd_state);
> >  
> >  	drm_connector_put(connector);
> >  }
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > index 146b83916005..00520867d37b 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
> >  	return intel_modeset_synced_crtcs(state, conn);
> >  }
> >  
> > -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> > +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
> >  {
> >  	struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
> >  	struct drm_i915_private *i915 = to_i915(connector->dev);
> > +	bool need_work = false;
> >  
> >  	spin_lock_irq(&i915->irq_lock);
> > -	i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > +	if (hpd_state != i915->hotplug.oob_hotplug_state) {
> > +		i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > +
> > +		i915->hotplug.oob_hotplug_state = hpd_state;
> > +		need_work = true;
> > +	}
> >  	spin_unlock_irq(&i915->irq_lock);
> > -	queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> > +
> > +	if (need_work)
> > +		queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> >  }
> >  
> >  static const struct drm_connector_funcs intel_dp_connector_funcs = {
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > index 8c1706fd81f9..543ebf1cfcf4 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -149,6 +149,9 @@ struct i915_hotplug {
> >  	/* Whether or not to count short HPD IRQs in HPD storms */
> >  	u8 hpd_short_storm_enabled;
> >  
> > +	/* Last state reported by oob_hotplug_event */
> > +	bool oob_hotplug_state;
> > +
> >  	/*
> >  	 * if we get a HPD irq from DP and a HPD irq from non-DP
> >  	 * the non-DP HPD could block the workqueue on a mode config
> > diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> > index c1d8c23baa39..a4596be4d34a 100644
> > --- a/drivers/usb/typec/altmodes/displayport.c
> > +++ b/drivers/usb/typec/altmodes/displayport.c
> > @@ -59,7 +59,6 @@ struct dp_altmode {
> >  	struct typec_displayport_data data;
> >  
> >  	enum dp_state state;
> > -	bool hpd;
> >  
> >  	struct mutex lock; /* device lock */
> >  	struct work_struct work;
> > @@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
> >  		if (!ret)
> >  			dp->state = DP_STATE_CONFIGURE;
> >  	} else {
> > -		if (dp->hpd != hpd) {
> > -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > -			dp->hpd = hpd;
> > -		}
> > +		drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
> >  	}
> >  
> >  	return ret;
> > @@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
> >  	cancel_work_sync(&dp->work);
> >  
> >  	if (dp->connector_fwnode) {
> > -		if (dp->hpd)
> > -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > +		drm_connector_oob_hotplug_event(dp->connector_fwnode, false);
> 
> See, what does "false" here mean?
> 
> Name the function for what it does, do not have random flags as
> parameters, that makes it impossible to understand what the code is
> doing when you are reading it, without having to jump around and figure
> out what the flags are saying.
> 
> And here they just don't even seem to be right :(
> 

Both the old and new code will signal to the DRM driver that the cable
was removed, the change is that we're carrying the level in the call
rather than just indicating that the state has changed.

We could introduce some HPD_HIGH/HPD_LOW defines to make it easier to
read. But the various places I'm looking at just represented the hpd
state as a bool.

Regards,
Bjorn

Re: [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Bjorn Andersson]

On Tue 08 Feb 02:39 PST 2022, Greg Kroah-Hartman wrote:

> On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> > In some implementations, such as the Qualcomm platforms, the display
> > driver has no way to query the current HPD state and as such it's
> > impossible to distinguish between disconnect and attention events.
> > 
> > Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> > state.
> > 
> > Also push the test for unchanged state in the displayport altmode driver
> > into the i915 driver, to allow other drivers to act upon each update.
> > 
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > ---
> > 
> > Note that the Intel driver has only been compile tested with this patch.
> > 
> >  drivers/gpu/drm/drm_connector.c          |  6 ++++--
> >  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
> >  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
> >  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
> >  include/drm/drm_connector.h              |  5 +++--
> >  5 files changed, 23 insertions(+), 14 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> > index a50c82bc2b2f..ad7295597c0f 100644
> > --- a/drivers/gpu/drm/drm_connector.c
> > +++ b/drivers/gpu/drm/drm_connector.c
> > @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> >  /**
> >   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
> >   * @connector_fwnode: fwnode_handle to report the event on
> > + * @hpd_state: number of data lanes available
> 
> "number"?
> 
> >   *
> >   * On some hardware a hotplug event notification may come from outside the display
> >   * driver / device. An example of this is some USB Type-C setups where the hardware
> > @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> >   * This function can be used to report these out-of-band events after obtaining
> >   * a drm_connector reference through calling drm_connector_find_by_fwnode().
> >   */
> > -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> > +				     bool hpd_state)
> 
> This is a boolean, how can it be a number?
> 

The kerneldoc wasn't appropriately updated as this went from being
"number of data lanes" to "the hot plug detect (hpd) state".

> And having a "flag" like this is a pain, how do you know what the
> parameter really means?
> 

You're right, "state" isn't a boolean property, let's rename it
"hpd_high" to clarify it.

> >  {
> >  	struct drm_connector *connector;
> >  
> > @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> >  		return;
> >  
> >  	if (connector->funcs->oob_hotplug_event)
> > -		connector->funcs->oob_hotplug_event(connector);
> > +		connector->funcs->oob_hotplug_event(connector, hpd_state);
> >  
> >  	drm_connector_put(connector);
> >  }
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > index 146b83916005..00520867d37b 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
> >  	return intel_modeset_synced_crtcs(state, conn);
> >  }
> >  
> > -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> > +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
> >  {
> >  	struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
> >  	struct drm_i915_private *i915 = to_i915(connector->dev);
> > +	bool need_work = false;
> >  
> >  	spin_lock_irq(&i915->irq_lock);
> > -	i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > +	if (hpd_state != i915->hotplug.oob_hotplug_state) {
> > +		i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > +
> > +		i915->hotplug.oob_hotplug_state = hpd_state;
> > +		need_work = true;
> > +	}
> >  	spin_unlock_irq(&i915->irq_lock);
> > -	queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> > +
> > +	if (need_work)
> > +		queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> >  }
> >  
> >  static const struct drm_connector_funcs intel_dp_connector_funcs = {
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > index 8c1706fd81f9..543ebf1cfcf4 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -149,6 +149,9 @@ struct i915_hotplug {
> >  	/* Whether or not to count short HPD IRQs in HPD storms */
> >  	u8 hpd_short_storm_enabled;
> >  
> > +	/* Last state reported by oob_hotplug_event */
> > +	bool oob_hotplug_state;
> > +
> >  	/*
> >  	 * if we get a HPD irq from DP and a HPD irq from non-DP
> >  	 * the non-DP HPD could block the workqueue on a mode config
> > diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> > index c1d8c23baa39..a4596be4d34a 100644
> > --- a/drivers/usb/typec/altmodes/displayport.c
> > +++ b/drivers/usb/typec/altmodes/displayport.c
> > @@ -59,7 +59,6 @@ struct dp_altmode {
> >  	struct typec_displayport_data data;
> >  
> >  	enum dp_state state;
> > -	bool hpd;
> >  
> >  	struct mutex lock; /* device lock */
> >  	struct work_struct work;
> > @@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
> >  		if (!ret)
> >  			dp->state = DP_STATE_CONFIGURE;
> >  	} else {
> > -		if (dp->hpd != hpd) {
> > -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > -			dp->hpd = hpd;
> > -		}
> > +		drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
> >  	}
> >  
> >  	return ret;
> > @@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
> >  	cancel_work_sync(&dp->work);
> >  
> >  	if (dp->connector_fwnode) {
> > -		if (dp->hpd)
> > -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > +		drm_connector_oob_hotplug_event(dp->connector_fwnode, false);
> 
> See, what does "false" here mean?
> 
> Name the function for what it does, do not have random flags as
> parameters, that makes it impossible to understand what the code is
> doing when you are reading it, without having to jump around and figure
> out what the flags are saying.
> 
> And here they just don't even seem to be right :(
> 

Both the old and new code will signal to the DRM driver that the cable
was removed, the change is that we're carrying the level in the call
rather than just indicating that the state has changed.

We could introduce some HPD_HIGH/HPD_LOW defines to make it easier to
read. But the various places I'm looking at just represented the hpd
state as a bool.

Regards,
Bjorn

Re: [Intel-gfx] [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Bjorn Andersson]

On Tue 08 Feb 02:39 PST 2022, Greg Kroah-Hartman wrote:

> On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> > In some implementations, such as the Qualcomm platforms, the display
> > driver has no way to query the current HPD state and as such it's
> > impossible to distinguish between disconnect and attention events.
> > 
> > Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> > state.
> > 
> > Also push the test for unchanged state in the displayport altmode driver
> > into the i915 driver, to allow other drivers to act upon each update.
> > 
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > ---
> > 
> > Note that the Intel driver has only been compile tested with this patch.
> > 
> >  drivers/gpu/drm/drm_connector.c          |  6 ++++--
> >  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
> >  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
> >  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
> >  include/drm/drm_connector.h              |  5 +++--
> >  5 files changed, 23 insertions(+), 14 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> > index a50c82bc2b2f..ad7295597c0f 100644
> > --- a/drivers/gpu/drm/drm_connector.c
> > +++ b/drivers/gpu/drm/drm_connector.c
> > @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> >  /**
> >   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
> >   * @connector_fwnode: fwnode_handle to report the event on
> > + * @hpd_state: number of data lanes available
> 
> "number"?
> 
> >   *
> >   * On some hardware a hotplug event notification may come from outside the display
> >   * driver / device. An example of this is some USB Type-C setups where the hardware
> > @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> >   * This function can be used to report these out-of-band events after obtaining
> >   * a drm_connector reference through calling drm_connector_find_by_fwnode().
> >   */
> > -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> > +				     bool hpd_state)
> 
> This is a boolean, how can it be a number?
> 

The kerneldoc wasn't appropriately updated as this went from being
"number of data lanes" to "the hot plug detect (hpd) state".

> And having a "flag" like this is a pain, how do you know what the
> parameter really means?
> 

You're right, "state" isn't a boolean property, let's rename it
"hpd_high" to clarify it.

> >  {
> >  	struct drm_connector *connector;
> >  
> > @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> >  		return;
> >  
> >  	if (connector->funcs->oob_hotplug_event)
> > -		connector->funcs->oob_hotplug_event(connector);
> > +		connector->funcs->oob_hotplug_event(connector, hpd_state);
> >  
> >  	drm_connector_put(connector);
> >  }
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > index 146b83916005..00520867d37b 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
> >  	return intel_modeset_synced_crtcs(state, conn);
> >  }
> >  
> > -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> > +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
> >  {
> >  	struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
> >  	struct drm_i915_private *i915 = to_i915(connector->dev);
> > +	bool need_work = false;
> >  
> >  	spin_lock_irq(&i915->irq_lock);
> > -	i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > +	if (hpd_state != i915->hotplug.oob_hotplug_state) {
> > +		i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > +
> > +		i915->hotplug.oob_hotplug_state = hpd_state;
> > +		need_work = true;
> > +	}
> >  	spin_unlock_irq(&i915->irq_lock);
> > -	queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> > +
> > +	if (need_work)
> > +		queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> >  }
> >  
> >  static const struct drm_connector_funcs intel_dp_connector_funcs = {
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > index 8c1706fd81f9..543ebf1cfcf4 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -149,6 +149,9 @@ struct i915_hotplug {
> >  	/* Whether or not to count short HPD IRQs in HPD storms */
> >  	u8 hpd_short_storm_enabled;
> >  
> > +	/* Last state reported by oob_hotplug_event */
> > +	bool oob_hotplug_state;
> > +
> >  	/*
> >  	 * if we get a HPD irq from DP and a HPD irq from non-DP
> >  	 * the non-DP HPD could block the workqueue on a mode config
> > diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> > index c1d8c23baa39..a4596be4d34a 100644
> > --- a/drivers/usb/typec/altmodes/displayport.c
> > +++ b/drivers/usb/typec/altmodes/displayport.c
> > @@ -59,7 +59,6 @@ struct dp_altmode {
> >  	struct typec_displayport_data data;
> >  
> >  	enum dp_state state;
> > -	bool hpd;
> >  
> >  	struct mutex lock; /* device lock */
> >  	struct work_struct work;
> > @@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
> >  		if (!ret)
> >  			dp->state = DP_STATE_CONFIGURE;
> >  	} else {
> > -		if (dp->hpd != hpd) {
> > -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > -			dp->hpd = hpd;
> > -		}
> > +		drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
> >  	}
> >  
> >  	return ret;
> > @@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
> >  	cancel_work_sync(&dp->work);
> >  
> >  	if (dp->connector_fwnode) {
> > -		if (dp->hpd)
> > -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > +		drm_connector_oob_hotplug_event(dp->connector_fwnode, false);
> 
> See, what does "false" here mean?
> 
> Name the function for what it does, do not have random flags as
> parameters, that makes it impossible to understand what the code is
> doing when you are reading it, without having to jump around and figure
> out what the flags are saying.
> 
> And here they just don't even seem to be right :(
> 

Both the old and new code will signal to the DRM driver that the cable
was removed, the change is that we're carrying the level in the call
rather than just indicating that the state has changed.

We could introduce some HPD_HIGH/HPD_LOW defines to make it easier to
read. But the various places I'm looking at just represented the hpd
state as a bool.

Regards,
Bjorn

Re: [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Dmitry Baryshkov]

On Thu, 10 Feb 2022 at 23:54, Bjorn Andersson
<bjorn.andersson@linaro.org> wrote:
>
> On Tue 08 Feb 02:39 PST 2022, Greg Kroah-Hartman wrote:
>
> > On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> > > In some implementations, such as the Qualcomm platforms, the display
> > > driver has no way to query the current HPD state and as such it's
> > > impossible to distinguish between disconnect and attention events.
> > >
> > > Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> > > state.
> > >
> > > Also push the test for unchanged state in the displayport altmode driver
> > > into the i915 driver, to allow other drivers to act upon each update.
> > >
> > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > > ---
> > >
> > > Note that the Intel driver has only been compile tested with this patch.
> > >
> > >  drivers/gpu/drm/drm_connector.c          |  6 ++++--
> > >  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
> > >  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
> > >  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
> > >  include/drm/drm_connector.h              |  5 +++--
> > >  5 files changed, 23 insertions(+), 14 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> > > index a50c82bc2b2f..ad7295597c0f 100644
> > > --- a/drivers/gpu/drm/drm_connector.c
> > > +++ b/drivers/gpu/drm/drm_connector.c
> > > @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> > >  /**
> > >   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
> > >   * @connector_fwnode: fwnode_handle to report the event on
> > > + * @hpd_state: number of data lanes available
> >
> > "number"?
> >
> > >   *
> > >   * On some hardware a hotplug event notification may come from outside the display
> > >   * driver / device. An example of this is some USB Type-C setups where the hardware
> > > @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> > >   * This function can be used to report these out-of-band events after obtaining
> > >   * a drm_connector reference through calling drm_connector_find_by_fwnode().
> > >   */
> > > -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > > +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> > > +                                bool hpd_state)
> >
> > This is a boolean, how can it be a number?
> >
>
> The kerneldoc wasn't appropriately updated as this went from being
> "number of data lanes" to "the hot plug detect (hpd) state".
>
> > And having a "flag" like this is a pain, how do you know what the
> > parameter really means?
> >
>
> You're right, "state" isn't a boolean property, let's rename it
> "hpd_high" to clarify it.

"connected" ?

>
> > >  {
> > >     struct drm_connector *connector;
> > >
> > > @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > >             return;
> > >
> > >     if (connector->funcs->oob_hotplug_event)
> > > -           connector->funcs->oob_hotplug_event(connector);
> > > +           connector->funcs->oob_hotplug_event(connector, hpd_state);
> > >
> > >     drm_connector_put(connector);
> > >  }
> > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > > index 146b83916005..00520867d37b 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > > @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
> > >     return intel_modeset_synced_crtcs(state, conn);
> > >  }
> > >
> > > -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> > > +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
> > >  {
> > >     struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
> > >     struct drm_i915_private *i915 = to_i915(connector->dev);
> > > +   bool need_work = false;
> > >
> > >     spin_lock_irq(&i915->irq_lock);
> > > -   i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > > +   if (hpd_state != i915->hotplug.oob_hotplug_state) {
> > > +           i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > > +
> > > +           i915->hotplug.oob_hotplug_state = hpd_state;
> > > +           need_work = true;
> > > +   }
> > >     spin_unlock_irq(&i915->irq_lock);
> > > -   queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> > > +
> > > +   if (need_work)
> > > +           queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> > >  }
> > >
> > >  static const struct drm_connector_funcs intel_dp_connector_funcs = {
> > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > > index 8c1706fd81f9..543ebf1cfcf4 100644
> > > --- a/drivers/gpu/drm/i915/i915_drv.h
> > > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > > @@ -149,6 +149,9 @@ struct i915_hotplug {
> > >     /* Whether or not to count short HPD IRQs in HPD storms */
> > >     u8 hpd_short_storm_enabled;
> > >
> > > +   /* Last state reported by oob_hotplug_event */
> > > +   bool oob_hotplug_state;
> > > +
> > >     /*
> > >      * if we get a HPD irq from DP and a HPD irq from non-DP
> > >      * the non-DP HPD could block the workqueue on a mode config
> > > diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> > > index c1d8c23baa39..a4596be4d34a 100644
> > > --- a/drivers/usb/typec/altmodes/displayport.c
> > > +++ b/drivers/usb/typec/altmodes/displayport.c
> > > @@ -59,7 +59,6 @@ struct dp_altmode {
> > >     struct typec_displayport_data data;
> > >
> > >     enum dp_state state;
> > > -   bool hpd;
> > >
> > >     struct mutex lock; /* device lock */
> > >     struct work_struct work;
> > > @@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
> > >             if (!ret)
> > >                     dp->state = DP_STATE_CONFIGURE;
> > >     } else {
> > > -           if (dp->hpd != hpd) {
> > > -                   drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > > -                   dp->hpd = hpd;
> > > -           }
> > > +           drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
> > >     }
> > >
> > >     return ret;
> > > @@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
> > >     cancel_work_sync(&dp->work);
> > >
> > >     if (dp->connector_fwnode) {
> > > -           if (dp->hpd)
> > > -                   drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > > +           drm_connector_oob_hotplug_event(dp->connector_fwnode, false);
> >
> > See, what does "false" here mean?
> >
> > Name the function for what it does, do not have random flags as
> > parameters, that makes it impossible to understand what the code is
> > doing when you are reading it, without having to jump around and figure
> > out what the flags are saying.
> >
> > And here they just don't even seem to be right :(
> >
>
> Both the old and new code will signal to the DRM driver that the cable
> was removed, the change is that we're carrying the level in the call
> rather than just indicating that the state has changed.
>
> We could introduce some HPD_HIGH/HPD_LOW defines to make it easier to
> read. But the various places I'm looking at just represented the hpd
> state as a bool.
>
> Regards,
> Bjorn



-- 
With best wishes
Dmitry

Re: [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Dmitry Baryshkov]

On Thu, 10 Feb 2022 at 23:54, Bjorn Andersson
<bjorn.andersson@linaro.org> wrote:
>
> On Tue 08 Feb 02:39 PST 2022, Greg Kroah-Hartman wrote:
>
> > On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> > > In some implementations, such as the Qualcomm platforms, the display
> > > driver has no way to query the current HPD state and as such it's
> > > impossible to distinguish between disconnect and attention events.
> > >
> > > Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> > > state.
> > >
> > > Also push the test for unchanged state in the displayport altmode driver
> > > into the i915 driver, to allow other drivers to act upon each update.
> > >
> > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > > ---
> > >
> > > Note that the Intel driver has only been compile tested with this patch.
> > >
> > >  drivers/gpu/drm/drm_connector.c          |  6 ++++--
> > >  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
> > >  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
> > >  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
> > >  include/drm/drm_connector.h              |  5 +++--
> > >  5 files changed, 23 insertions(+), 14 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> > > index a50c82bc2b2f..ad7295597c0f 100644
> > > --- a/drivers/gpu/drm/drm_connector.c
> > > +++ b/drivers/gpu/drm/drm_connector.c
> > > @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> > >  /**
> > >   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
> > >   * @connector_fwnode: fwnode_handle to report the event on
> > > + * @hpd_state: number of data lanes available
> >
> > "number"?
> >
> > >   *
> > >   * On some hardware a hotplug event notification may come from outside the display
> > >   * driver / device. An example of this is some USB Type-C setups where the hardware
> > > @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> > >   * This function can be used to report these out-of-band events after obtaining
> > >   * a drm_connector reference through calling drm_connector_find_by_fwnode().
> > >   */
> > > -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > > +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> > > +                                bool hpd_state)
> >
> > This is a boolean, how can it be a number?
> >
>
> The kerneldoc wasn't appropriately updated as this went from being
> "number of data lanes" to "the hot plug detect (hpd) state".
>
> > And having a "flag" like this is a pain, how do you know what the
> > parameter really means?
> >
>
> You're right, "state" isn't a boolean property, let's rename it
> "hpd_high" to clarify it.

"connected" ?

>
> > >  {
> > >     struct drm_connector *connector;
> > >
> > > @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > >             return;
> > >
> > >     if (connector->funcs->oob_hotplug_event)
> > > -           connector->funcs->oob_hotplug_event(connector);
> > > +           connector->funcs->oob_hotplug_event(connector, hpd_state);
> > >
> > >     drm_connector_put(connector);
> > >  }
> > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > > index 146b83916005..00520867d37b 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > > @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
> > >     return intel_modeset_synced_crtcs(state, conn);
> > >  }
> > >
> > > -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> > > +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
> > >  {
> > >     struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
> > >     struct drm_i915_private *i915 = to_i915(connector->dev);
> > > +   bool need_work = false;
> > >
> > >     spin_lock_irq(&i915->irq_lock);
> > > -   i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > > +   if (hpd_state != i915->hotplug.oob_hotplug_state) {
> > > +           i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > > +
> > > +           i915->hotplug.oob_hotplug_state = hpd_state;
> > > +           need_work = true;
> > > +   }
> > >     spin_unlock_irq(&i915->irq_lock);
> > > -   queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> > > +
> > > +   if (need_work)
> > > +           queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> > >  }
> > >
> > >  static const struct drm_connector_funcs intel_dp_connector_funcs = {
> > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > > index 8c1706fd81f9..543ebf1cfcf4 100644
> > > --- a/drivers/gpu/drm/i915/i915_drv.h
> > > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > > @@ -149,6 +149,9 @@ struct i915_hotplug {
> > >     /* Whether or not to count short HPD IRQs in HPD storms */
> > >     u8 hpd_short_storm_enabled;
> > >
> > > +   /* Last state reported by oob_hotplug_event */
> > > +   bool oob_hotplug_state;
> > > +
> > >     /*
> > >      * if we get a HPD irq from DP and a HPD irq from non-DP
> > >      * the non-DP HPD could block the workqueue on a mode config
> > > diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> > > index c1d8c23baa39..a4596be4d34a 100644
> > > --- a/drivers/usb/typec/altmodes/displayport.c
> > > +++ b/drivers/usb/typec/altmodes/displayport.c
> > > @@ -59,7 +59,6 @@ struct dp_altmode {
> > >     struct typec_displayport_data data;
> > >
> > >     enum dp_state state;
> > > -   bool hpd;
> > >
> > >     struct mutex lock; /* device lock */
> > >     struct work_struct work;
> > > @@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
> > >             if (!ret)
> > >                     dp->state = DP_STATE_CONFIGURE;
> > >     } else {
> > > -           if (dp->hpd != hpd) {
> > > -                   drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > > -                   dp->hpd = hpd;
> > > -           }
> > > +           drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
> > >     }
> > >
> > >     return ret;
> > > @@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
> > >     cancel_work_sync(&dp->work);
> > >
> > >     if (dp->connector_fwnode) {
> > > -           if (dp->hpd)
> > > -                   drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > > +           drm_connector_oob_hotplug_event(dp->connector_fwnode, false);
> >
> > See, what does "false" here mean?
> >
> > Name the function for what it does, do not have random flags as
> > parameters, that makes it impossible to understand what the code is
> > doing when you are reading it, without having to jump around and figure
> > out what the flags are saying.
> >
> > And here they just don't even seem to be right :(
> >
>
> Both the old and new code will signal to the DRM driver that the cable
> was removed, the change is that we're carrying the level in the call
> rather than just indicating that the state has changed.
>
> We could introduce some HPD_HIGH/HPD_LOW defines to make it easier to
> read. But the various places I'm looking at just represented the hpd
> state as a bool.
>
> Regards,
> Bjorn



-- 
With best wishes
Dmitry

Re: [Intel-gfx] [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Dmitry Baryshkov]

On Thu, 10 Feb 2022 at 23:54, Bjorn Andersson
<bjorn.andersson@linaro.org> wrote:
>
> On Tue 08 Feb 02:39 PST 2022, Greg Kroah-Hartman wrote:
>
> > On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> > > In some implementations, such as the Qualcomm platforms, the display
> > > driver has no way to query the current HPD state and as such it's
> > > impossible to distinguish between disconnect and attention events.
> > >
> > > Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> > > state.
> > >
> > > Also push the test for unchanged state in the displayport altmode driver
> > > into the i915 driver, to allow other drivers to act upon each update.
> > >
> > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > > ---
> > >
> > > Note that the Intel driver has only been compile tested with this patch.
> > >
> > >  drivers/gpu/drm/drm_connector.c          |  6 ++++--
> > >  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
> > >  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
> > >  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
> > >  include/drm/drm_connector.h              |  5 +++--
> > >  5 files changed, 23 insertions(+), 14 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> > > index a50c82bc2b2f..ad7295597c0f 100644
> > > --- a/drivers/gpu/drm/drm_connector.c
> > > +++ b/drivers/gpu/drm/drm_connector.c
> > > @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> > >  /**
> > >   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
> > >   * @connector_fwnode: fwnode_handle to report the event on
> > > + * @hpd_state: number of data lanes available
> >
> > "number"?
> >
> > >   *
> > >   * On some hardware a hotplug event notification may come from outside the display
> > >   * driver / device. An example of this is some USB Type-C setups where the hardware
> > > @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> > >   * This function can be used to report these out-of-band events after obtaining
> > >   * a drm_connector reference through calling drm_connector_find_by_fwnode().
> > >   */
> > > -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > > +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> > > +                                bool hpd_state)
> >
> > This is a boolean, how can it be a number?
> >
>
> The kerneldoc wasn't appropriately updated as this went from being
> "number of data lanes" to "the hot plug detect (hpd) state".
>
> > And having a "flag" like this is a pain, how do you know what the
> > parameter really means?
> >
>
> You're right, "state" isn't a boolean property, let's rename it
> "hpd_high" to clarify it.

"connected" ?

>
> > >  {
> > >     struct drm_connector *connector;
> > >
> > > @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > >             return;
> > >
> > >     if (connector->funcs->oob_hotplug_event)
> > > -           connector->funcs->oob_hotplug_event(connector);
> > > +           connector->funcs->oob_hotplug_event(connector, hpd_state);
> > >
> > >     drm_connector_put(connector);
> > >  }
> > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > > index 146b83916005..00520867d37b 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > > @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
> > >     return intel_modeset_synced_crtcs(state, conn);
> > >  }
> > >
> > > -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> > > +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
> > >  {
> > >     struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
> > >     struct drm_i915_private *i915 = to_i915(connector->dev);
> > > +   bool need_work = false;
> > >
> > >     spin_lock_irq(&i915->irq_lock);
> > > -   i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > > +   if (hpd_state != i915->hotplug.oob_hotplug_state) {
> > > +           i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > > +
> > > +           i915->hotplug.oob_hotplug_state = hpd_state;
> > > +           need_work = true;
> > > +   }
> > >     spin_unlock_irq(&i915->irq_lock);
> > > -   queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> > > +
> > > +   if (need_work)
> > > +           queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> > >  }
> > >
> > >  static const struct drm_connector_funcs intel_dp_connector_funcs = {
> > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > > index 8c1706fd81f9..543ebf1cfcf4 100644
> > > --- a/drivers/gpu/drm/i915/i915_drv.h
> > > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > > @@ -149,6 +149,9 @@ struct i915_hotplug {
> > >     /* Whether or not to count short HPD IRQs in HPD storms */
> > >     u8 hpd_short_storm_enabled;
> > >
> > > +   /* Last state reported by oob_hotplug_event */
> > > +   bool oob_hotplug_state;
> > > +
> > >     /*
> > >      * if we get a HPD irq from DP and a HPD irq from non-DP
> > >      * the non-DP HPD could block the workqueue on a mode config
> > > diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> > > index c1d8c23baa39..a4596be4d34a 100644
> > > --- a/drivers/usb/typec/altmodes/displayport.c
> > > +++ b/drivers/usb/typec/altmodes/displayport.c
> > > @@ -59,7 +59,6 @@ struct dp_altmode {
> > >     struct typec_displayport_data data;
> > >
> > >     enum dp_state state;
> > > -   bool hpd;
> > >
> > >     struct mutex lock; /* device lock */
> > >     struct work_struct work;
> > > @@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
> > >             if (!ret)
> > >                     dp->state = DP_STATE_CONFIGURE;
> > >     } else {
> > > -           if (dp->hpd != hpd) {
> > > -                   drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > > -                   dp->hpd = hpd;
> > > -           }
> > > +           drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
> > >     }
> > >
> > >     return ret;
> > > @@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
> > >     cancel_work_sync(&dp->work);
> > >
> > >     if (dp->connector_fwnode) {
> > > -           if (dp->hpd)
> > > -                   drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > > +           drm_connector_oob_hotplug_event(dp->connector_fwnode, false);
> >
> > See, what does "false" here mean?
> >
> > Name the function for what it does, do not have random flags as
> > parameters, that makes it impossible to understand what the code is
> > doing when you are reading it, without having to jump around and figure
> > out what the flags are saying.
> >
> > And here they just don't even seem to be right :(
> >
>
> Both the old and new code will signal to the DRM driver that the cable
> was removed, the change is that we're carrying the level in the call
> rather than just indicating that the state has changed.
>
> We could introduce some HPD_HIGH/HPD_LOW defines to make it easier to
> read. But the various places I'm looking at just represented the hpd
> state as a bool.
>
> Regards,
> Bjorn



-- 
With best wishes
Dmitry

Re: [PATCH 2/2] drm/msm/dp: Implement oob_hotplug_event()

[Bjorn Andersson]

On Mon 07 Feb 23:40 PST 2022, Greg Kroah-Hartman wrote:

> On Mon, Feb 07, 2022 at 08:43:28PM -0800, Bjorn Andersson wrote:
> > The Qualcomm DisplayPort driver contains traces of the necessary
> > plumbing to hook up USB HPD, in the form of the dp_hpd module and the
> > dp_usbpd_cb struct. Use this as basis for implementing the
> > oob_hotplug_event() callback, by amending the dp_hpd module with the
> > missing logic.
> > 
> > Overall the solution is similar to what's done downstream, but upstream
> > all the code to disect the HPD notification lives on the calling side of
> > drm_connector_oob_hotplug_event().
> > 
> > drm_connector_oob_hotplug_event() performs the lookup of the
> > drm_connector based on fwnode, hence the need to assign the fwnode in
> > dp_drm_connector_init().
> > 
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > ---
> >  drivers/gpu/drm/msm/dp/dp_display.c |  8 ++++++++
> >  drivers/gpu/drm/msm/dp/dp_display.h |  2 ++
> >  drivers/gpu/drm/msm/dp/dp_drm.c     | 10 ++++++++++
> >  drivers/gpu/drm/msm/dp/dp_hpd.c     | 19 +++++++++++++++++++
> >  drivers/gpu/drm/msm/dp/dp_hpd.h     |  4 ++++
> >  5 files changed, 43 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> > index 7cc4d21f2091..124a2f794382 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_display.c
> > +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> > @@ -414,6 +414,13 @@ static int dp_display_usbpd_configure_cb(struct device *dev)
> >  	return dp_display_process_hpd_high(dp);
> >  }
> >  
> > +void dp_display_oob_hotplug_event(struct msm_dp *dp_display, bool hpd_state)
> > +{
> > +	struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);
> > +
> > +	dp->usbpd->oob_event(dp->usbpd, hpd_state);
> > +}
> > +
> >  static int dp_display_usbpd_disconnect_cb(struct device *dev)
> >  {
> >  	struct dp_display_private *dp = dev_get_dp_display_private(dev);
> > @@ -1251,6 +1258,7 @@ static int dp_display_probe(struct platform_device *pdev)
> >  	dp->pdev = pdev;
> >  	dp->name = "drm_dp";
> >  	dp->dp_display.connector_type = desc->connector_type;
> > +	dp->dp_display.dev = &pdev->dev;
> 
> You did not properly reference count this pointer you just saved.  What
> is to keep that pointer from going away without you knowing about it?
> 

The "dp" object only lives while &pdev->dev is alive, both logically and
as its devres allocated on &pdev-dev. So for this reference I don't see
that we should refcount it.

> And you already have a pointer to pdev, why save another one here?
> 

The Qualcomm DisplayPort driver has per-c-file private context structs
and "dp" is one such object. So I simply can't dereference it and get to
pdev from the other c-file in the same driver...

But I only need it in dp_drm.c to during initialization to get a
reference to the associated fwnode, so it seems that I can rework this
and pass the pointer as a parameter to dp_drm_connector_init().

That looks to be cleaner as well.

Thanks,
Bjorn

Re: [PATCH 2/2] drm/msm/dp: Implement oob_hotplug_event()

[Bjorn Andersson]

On Mon 07 Feb 23:40 PST 2022, Greg Kroah-Hartman wrote:

> On Mon, Feb 07, 2022 at 08:43:28PM -0800, Bjorn Andersson wrote:
> > The Qualcomm DisplayPort driver contains traces of the necessary
> > plumbing to hook up USB HPD, in the form of the dp_hpd module and the
> > dp_usbpd_cb struct. Use this as basis for implementing the
> > oob_hotplug_event() callback, by amending the dp_hpd module with the
> > missing logic.
> > 
> > Overall the solution is similar to what's done downstream, but upstream
> > all the code to disect the HPD notification lives on the calling side of
> > drm_connector_oob_hotplug_event().
> > 
> > drm_connector_oob_hotplug_event() performs the lookup of the
> > drm_connector based on fwnode, hence the need to assign the fwnode in
> > dp_drm_connector_init().
> > 
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > ---
> >  drivers/gpu/drm/msm/dp/dp_display.c |  8 ++++++++
> >  drivers/gpu/drm/msm/dp/dp_display.h |  2 ++
> >  drivers/gpu/drm/msm/dp/dp_drm.c     | 10 ++++++++++
> >  drivers/gpu/drm/msm/dp/dp_hpd.c     | 19 +++++++++++++++++++
> >  drivers/gpu/drm/msm/dp/dp_hpd.h     |  4 ++++
> >  5 files changed, 43 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> > index 7cc4d21f2091..124a2f794382 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_display.c
> > +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> > @@ -414,6 +414,13 @@ static int dp_display_usbpd_configure_cb(struct device *dev)
> >  	return dp_display_process_hpd_high(dp);
> >  }
> >  
> > +void dp_display_oob_hotplug_event(struct msm_dp *dp_display, bool hpd_state)
> > +{
> > +	struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);
> > +
> > +	dp->usbpd->oob_event(dp->usbpd, hpd_state);
> > +}
> > +
> >  static int dp_display_usbpd_disconnect_cb(struct device *dev)
> >  {
> >  	struct dp_display_private *dp = dev_get_dp_display_private(dev);
> > @@ -1251,6 +1258,7 @@ static int dp_display_probe(struct platform_device *pdev)
> >  	dp->pdev = pdev;
> >  	dp->name = "drm_dp";
> >  	dp->dp_display.connector_type = desc->connector_type;
> > +	dp->dp_display.dev = &pdev->dev;
> 
> You did not properly reference count this pointer you just saved.  What
> is to keep that pointer from going away without you knowing about it?
> 

The "dp" object only lives while &pdev->dev is alive, both logically and
as its devres allocated on &pdev-dev. So for this reference I don't see
that we should refcount it.

> And you already have a pointer to pdev, why save another one here?
> 

The Qualcomm DisplayPort driver has per-c-file private context structs
and "dp" is one such object. So I simply can't dereference it and get to
pdev from the other c-file in the same driver...

But I only need it in dp_drm.c to during initialization to get a
reference to the associated fwnode, so it seems that I can rework this
and pass the pointer as a parameter to dp_drm_connector_init().

That looks to be cleaner as well.

Thanks,
Bjorn

Re: [Intel-gfx] [PATCH 2/2] drm/msm/dp: Implement oob_hotplug_event()

[Bjorn Andersson]

On Mon 07 Feb 23:40 PST 2022, Greg Kroah-Hartman wrote:

> On Mon, Feb 07, 2022 at 08:43:28PM -0800, Bjorn Andersson wrote:
> > The Qualcomm DisplayPort driver contains traces of the necessary
> > plumbing to hook up USB HPD, in the form of the dp_hpd module and the
> > dp_usbpd_cb struct. Use this as basis for implementing the
> > oob_hotplug_event() callback, by amending the dp_hpd module with the
> > missing logic.
> > 
> > Overall the solution is similar to what's done downstream, but upstream
> > all the code to disect the HPD notification lives on the calling side of
> > drm_connector_oob_hotplug_event().
> > 
> > drm_connector_oob_hotplug_event() performs the lookup of the
> > drm_connector based on fwnode, hence the need to assign the fwnode in
> > dp_drm_connector_init().
> > 
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > ---
> >  drivers/gpu/drm/msm/dp/dp_display.c |  8 ++++++++
> >  drivers/gpu/drm/msm/dp/dp_display.h |  2 ++
> >  drivers/gpu/drm/msm/dp/dp_drm.c     | 10 ++++++++++
> >  drivers/gpu/drm/msm/dp/dp_hpd.c     | 19 +++++++++++++++++++
> >  drivers/gpu/drm/msm/dp/dp_hpd.h     |  4 ++++
> >  5 files changed, 43 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> > index 7cc4d21f2091..124a2f794382 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_display.c
> > +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> > @@ -414,6 +414,13 @@ static int dp_display_usbpd_configure_cb(struct device *dev)
> >  	return dp_display_process_hpd_high(dp);
> >  }
> >  
> > +void dp_display_oob_hotplug_event(struct msm_dp *dp_display, bool hpd_state)
> > +{
> > +	struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);
> > +
> > +	dp->usbpd->oob_event(dp->usbpd, hpd_state);
> > +}
> > +
> >  static int dp_display_usbpd_disconnect_cb(struct device *dev)
> >  {
> >  	struct dp_display_private *dp = dev_get_dp_display_private(dev);
> > @@ -1251,6 +1258,7 @@ static int dp_display_probe(struct platform_device *pdev)
> >  	dp->pdev = pdev;
> >  	dp->name = "drm_dp";
> >  	dp->dp_display.connector_type = desc->connector_type;
> > +	dp->dp_display.dev = &pdev->dev;
> 
> You did not properly reference count this pointer you just saved.  What
> is to keep that pointer from going away without you knowing about it?
> 

The "dp" object only lives while &pdev->dev is alive, both logically and
as its devres allocated on &pdev-dev. So for this reference I don't see
that we should refcount it.

> And you already have a pointer to pdev, why save another one here?
> 

The Qualcomm DisplayPort driver has per-c-file private context structs
and "dp" is one such object. So I simply can't dereference it and get to
pdev from the other c-file in the same driver...

But I only need it in dp_drm.c to during initialization to get a
reference to the associated fwnode, so it seems that I can rework this
and pass the pointer as a parameter to dp_drm_connector_init().

That looks to be cleaner as well.

Thanks,
Bjorn

Re: [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Bjorn Andersson]

On Thu 10 Feb 13:12 PST 2022, Dmitry Baryshkov wrote:

> On Thu, 10 Feb 2022 at 23:54, Bjorn Andersson
> <bjorn.andersson@linaro.org> wrote:
> >
> > On Tue 08 Feb 02:39 PST 2022, Greg Kroah-Hartman wrote:
> >
> > > On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> > > > In some implementations, such as the Qualcomm platforms, the display
> > > > driver has no way to query the current HPD state and as such it's
> > > > impossible to distinguish between disconnect and attention events.
> > > >
> > > > Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> > > > state.
> > > >
> > > > Also push the test for unchanged state in the displayport altmode driver
> > > > into the i915 driver, to allow other drivers to act upon each update.
> > > >
> > > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > > > ---
> > > >
> > > > Note that the Intel driver has only been compile tested with this patch.
> > > >
> > > >  drivers/gpu/drm/drm_connector.c          |  6 ++++--
> > > >  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
> > > >  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
> > > >  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
> > > >  include/drm/drm_connector.h              |  5 +++--
> > > >  5 files changed, 23 insertions(+), 14 deletions(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> > > > index a50c82bc2b2f..ad7295597c0f 100644
> > > > --- a/drivers/gpu/drm/drm_connector.c
> > > > +++ b/drivers/gpu/drm/drm_connector.c
> > > > @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> > > >  /**
> > > >   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
> > > >   * @connector_fwnode: fwnode_handle to report the event on
> > > > + * @hpd_state: number of data lanes available
> > >
> > > "number"?
> > >
> > > >   *
> > > >   * On some hardware a hotplug event notification may come from outside the display
> > > >   * driver / device. An example of this is some USB Type-C setups where the hardware
> > > > @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> > > >   * This function can be used to report these out-of-band events after obtaining
> > > >   * a drm_connector reference through calling drm_connector_find_by_fwnode().
> > > >   */
> > > > -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > > > +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> > > > +                                bool hpd_state)
> > >
> > > This is a boolean, how can it be a number?
> > >
> >
> > The kerneldoc wasn't appropriately updated as this went from being
> > "number of data lanes" to "the hot plug detect (hpd) state".
> >
> > > And having a "flag" like this is a pain, how do you know what the
> > > parameter really means?
> > >
> >
> > You're right, "state" isn't a boolean property, let's rename it
> > "hpd_high" to clarify it.
> 
> "connected" ?
> 

I've been trying to find some references to point to, but my
understanding is that in a DisplayPort or HDMI connector/cable you have
a dedicated HPD pin, which when high denotes the sink is alive _and_
EDID can be read.

So in a situation where you have a multifunction USB & DP/HDMI hub where
you connect a display, you might have the USB hub connected to the host
and you might even have your sink connected, but HPD could still be low
until the display is ready to talk to you. So physically everything is
connected, but this property will still be "not connected".

As such I don't think it's appropriate to name it "connected".

Regards,
Bjorn

> >
> > > >  {
> > > >     struct drm_connector *connector;
> > > >
> > > > @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > > >             return;
> > > >
> > > >     if (connector->funcs->oob_hotplug_event)
> > > > -           connector->funcs->oob_hotplug_event(connector);
> > > > +           connector->funcs->oob_hotplug_event(connector, hpd_state);
> > > >
> > > >     drm_connector_put(connector);
> > > >  }
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > > > index 146b83916005..00520867d37b 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > > > @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
> > > >     return intel_modeset_synced_crtcs(state, conn);
> > > >  }
> > > >
> > > > -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> > > > +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
> > > >  {
> > > >     struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
> > > >     struct drm_i915_private *i915 = to_i915(connector->dev);
> > > > +   bool need_work = false;
> > > >
> > > >     spin_lock_irq(&i915->irq_lock);
> > > > -   i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > > > +   if (hpd_state != i915->hotplug.oob_hotplug_state) {
> > > > +           i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > > > +
> > > > +           i915->hotplug.oob_hotplug_state = hpd_state;
> > > > +           need_work = true;
> > > > +   }
> > > >     spin_unlock_irq(&i915->irq_lock);
> > > > -   queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> > > > +
> > > > +   if (need_work)
> > > > +           queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> > > >  }
> > > >
> > > >  static const struct drm_connector_funcs intel_dp_connector_funcs = {
> > > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > > > index 8c1706fd81f9..543ebf1cfcf4 100644
> > > > --- a/drivers/gpu/drm/i915/i915_drv.h
> > > > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > > > @@ -149,6 +149,9 @@ struct i915_hotplug {
> > > >     /* Whether or not to count short HPD IRQs in HPD storms */
> > > >     u8 hpd_short_storm_enabled;
> > > >
> > > > +   /* Last state reported by oob_hotplug_event */
> > > > +   bool oob_hotplug_state;
> > > > +
> > > >     /*
> > > >      * if we get a HPD irq from DP and a HPD irq from non-DP
> > > >      * the non-DP HPD could block the workqueue on a mode config
> > > > diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> > > > index c1d8c23baa39..a4596be4d34a 100644
> > > > --- a/drivers/usb/typec/altmodes/displayport.c
> > > > +++ b/drivers/usb/typec/altmodes/displayport.c
> > > > @@ -59,7 +59,6 @@ struct dp_altmode {
> > > >     struct typec_displayport_data data;
> > > >
> > > >     enum dp_state state;
> > > > -   bool hpd;
> > > >
> > > >     struct mutex lock; /* device lock */
> > > >     struct work_struct work;
> > > > @@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
> > > >             if (!ret)
> > > >                     dp->state = DP_STATE_CONFIGURE;
> > > >     } else {
> > > > -           if (dp->hpd != hpd) {
> > > > -                   drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > > > -                   dp->hpd = hpd;
> > > > -           }
> > > > +           drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
> > > >     }
> > > >
> > > >     return ret;
> > > > @@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
> > > >     cancel_work_sync(&dp->work);
> > > >
> > > >     if (dp->connector_fwnode) {
> > > > -           if (dp->hpd)
> > > > -                   drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > > > +           drm_connector_oob_hotplug_event(dp->connector_fwnode, false);
> > >
> > > See, what does "false" here mean?
> > >
> > > Name the function for what it does, do not have random flags as
> > > parameters, that makes it impossible to understand what the code is
> > > doing when you are reading it, without having to jump around and figure
> > > out what the flags are saying.
> > >
> > > And here they just don't even seem to be right :(
> > >
> >
> > Both the old and new code will signal to the DRM driver that the cable
> > was removed, the change is that we're carrying the level in the call
> > rather than just indicating that the state has changed.
> >
> > We could introduce some HPD_HIGH/HPD_LOW defines to make it easier to
> > read. But the various places I'm looking at just represented the hpd
> > state as a bool.
> >
> > Regards,
> > Bjorn
> 
> 
> 
> -- 
> With best wishes
> Dmitry

Re: [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Bjorn Andersson]

On Thu 10 Feb 13:12 PST 2022, Dmitry Baryshkov wrote:

> On Thu, 10 Feb 2022 at 23:54, Bjorn Andersson
> <bjorn.andersson@linaro.org> wrote:
> >
> > On Tue 08 Feb 02:39 PST 2022, Greg Kroah-Hartman wrote:
> >
> > > On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> > > > In some implementations, such as the Qualcomm platforms, the display
> > > > driver has no way to query the current HPD state and as such it's
> > > > impossible to distinguish between disconnect and attention events.
> > > >
> > > > Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> > > > state.
> > > >
> > > > Also push the test for unchanged state in the displayport altmode driver
> > > > into the i915 driver, to allow other drivers to act upon each update.
> > > >
> > > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > > > ---
> > > >
> > > > Note that the Intel driver has only been compile tested with this patch.
> > > >
> > > >  drivers/gpu/drm/drm_connector.c          |  6 ++++--
> > > >  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
> > > >  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
> > > >  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
> > > >  include/drm/drm_connector.h              |  5 +++--
> > > >  5 files changed, 23 insertions(+), 14 deletions(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> > > > index a50c82bc2b2f..ad7295597c0f 100644
> > > > --- a/drivers/gpu/drm/drm_connector.c
> > > > +++ b/drivers/gpu/drm/drm_connector.c
> > > > @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> > > >  /**
> > > >   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
> > > >   * @connector_fwnode: fwnode_handle to report the event on
> > > > + * @hpd_state: number of data lanes available
> > >
> > > "number"?
> > >
> > > >   *
> > > >   * On some hardware a hotplug event notification may come from outside the display
> > > >   * driver / device. An example of this is some USB Type-C setups where the hardware
> > > > @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> > > >   * This function can be used to report these out-of-band events after obtaining
> > > >   * a drm_connector reference through calling drm_connector_find_by_fwnode().
> > > >   */
> > > > -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > > > +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> > > > +                                bool hpd_state)
> > >
> > > This is a boolean, how can it be a number?
> > >
> >
> > The kerneldoc wasn't appropriately updated as this went from being
> > "number of data lanes" to "the hot plug detect (hpd) state".
> >
> > > And having a "flag" like this is a pain, how do you know what the
> > > parameter really means?
> > >
> >
> > You're right, "state" isn't a boolean property, let's rename it
> > "hpd_high" to clarify it.
> 
> "connected" ?
> 

I've been trying to find some references to point to, but my
understanding is that in a DisplayPort or HDMI connector/cable you have
a dedicated HPD pin, which when high denotes the sink is alive _and_
EDID can be read.

So in a situation where you have a multifunction USB & DP/HDMI hub where
you connect a display, you might have the USB hub connected to the host
and you might even have your sink connected, but HPD could still be low
until the display is ready to talk to you. So physically everything is
connected, but this property will still be "not connected".

As such I don't think it's appropriate to name it "connected".

Regards,
Bjorn

> >
> > > >  {
> > > >     struct drm_connector *connector;
> > > >
> > > > @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > > >             return;
> > > >
> > > >     if (connector->funcs->oob_hotplug_event)
> > > > -           connector->funcs->oob_hotplug_event(connector);
> > > > +           connector->funcs->oob_hotplug_event(connector, hpd_state);
> > > >
> > > >     drm_connector_put(connector);
> > > >  }
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > > > index 146b83916005..00520867d37b 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > > > @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
> > > >     return intel_modeset_synced_crtcs(state, conn);
> > > >  }
> > > >
> > > > -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> > > > +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
> > > >  {
> > > >     struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
> > > >     struct drm_i915_private *i915 = to_i915(connector->dev);
> > > > +   bool need_work = false;
> > > >
> > > >     spin_lock_irq(&i915->irq_lock);
> > > > -   i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > > > +   if (hpd_state != i915->hotplug.oob_hotplug_state) {
> > > > +           i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > > > +
> > > > +           i915->hotplug.oob_hotplug_state = hpd_state;
> > > > +           need_work = true;
> > > > +   }
> > > >     spin_unlock_irq(&i915->irq_lock);
> > > > -   queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> > > > +
> > > > +   if (need_work)
> > > > +           queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> > > >  }
> > > >
> > > >  static const struct drm_connector_funcs intel_dp_connector_funcs = {
> > > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > > > index 8c1706fd81f9..543ebf1cfcf4 100644
> > > > --- a/drivers/gpu/drm/i915/i915_drv.h
> > > > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > > > @@ -149,6 +149,9 @@ struct i915_hotplug {
> > > >     /* Whether or not to count short HPD IRQs in HPD storms */
> > > >     u8 hpd_short_storm_enabled;
> > > >
> > > > +   /* Last state reported by oob_hotplug_event */
> > > > +   bool oob_hotplug_state;
> > > > +
> > > >     /*
> > > >      * if we get a HPD irq from DP and a HPD irq from non-DP
> > > >      * the non-DP HPD could block the workqueue on a mode config
> > > > diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> > > > index c1d8c23baa39..a4596be4d34a 100644
> > > > --- a/drivers/usb/typec/altmodes/displayport.c
> > > > +++ b/drivers/usb/typec/altmodes/displayport.c
> > > > @@ -59,7 +59,6 @@ struct dp_altmode {
> > > >     struct typec_displayport_data data;
> > > >
> > > >     enum dp_state state;
> > > > -   bool hpd;
> > > >
> > > >     struct mutex lock; /* device lock */
> > > >     struct work_struct work;
> > > > @@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
> > > >             if (!ret)
> > > >                     dp->state = DP_STATE_CONFIGURE;
> > > >     } else {
> > > > -           if (dp->hpd != hpd) {
> > > > -                   drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > > > -                   dp->hpd = hpd;
> > > > -           }
> > > > +           drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
> > > >     }
> > > >
> > > >     return ret;
> > > > @@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
> > > >     cancel_work_sync(&dp->work);
> > > >
> > > >     if (dp->connector_fwnode) {
> > > > -           if (dp->hpd)
> > > > -                   drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > > > +           drm_connector_oob_hotplug_event(dp->connector_fwnode, false);
> > >
> > > See, what does "false" here mean?
> > >
> > > Name the function for what it does, do not have random flags as
> > > parameters, that makes it impossible to understand what the code is
> > > doing when you are reading it, without having to jump around and figure
> > > out what the flags are saying.
> > >
> > > And here they just don't even seem to be right :(
> > >
> >
> > Both the old and new code will signal to the DRM driver that the cable
> > was removed, the change is that we're carrying the level in the call
> > rather than just indicating that the state has changed.
> >
> > We could introduce some HPD_HIGH/HPD_LOW defines to make it easier to
> > read. But the various places I'm looking at just represented the hpd
> > state as a bool.
> >
> > Regards,
> > Bjorn
> 
> 
> 
> -- 
> With best wishes
> Dmitry

Re: [Intel-gfx] [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Bjorn Andersson]

On Thu 10 Feb 13:12 PST 2022, Dmitry Baryshkov wrote:

> On Thu, 10 Feb 2022 at 23:54, Bjorn Andersson
> <bjorn.andersson@linaro.org> wrote:
> >
> > On Tue 08 Feb 02:39 PST 2022, Greg Kroah-Hartman wrote:
> >
> > > On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> > > > In some implementations, such as the Qualcomm platforms, the display
> > > > driver has no way to query the current HPD state and as such it's
> > > > impossible to distinguish between disconnect and attention events.
> > > >
> > > > Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> > > > state.
> > > >
> > > > Also push the test for unchanged state in the displayport altmode driver
> > > > into the i915 driver, to allow other drivers to act upon each update.
> > > >
> > > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > > > ---
> > > >
> > > > Note that the Intel driver has only been compile tested with this patch.
> > > >
> > > >  drivers/gpu/drm/drm_connector.c          |  6 ++++--
> > > >  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
> > > >  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
> > > >  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
> > > >  include/drm/drm_connector.h              |  5 +++--
> > > >  5 files changed, 23 insertions(+), 14 deletions(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> > > > index a50c82bc2b2f..ad7295597c0f 100644
> > > > --- a/drivers/gpu/drm/drm_connector.c
> > > > +++ b/drivers/gpu/drm/drm_connector.c
> > > > @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> > > >  /**
> > > >   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
> > > >   * @connector_fwnode: fwnode_handle to report the event on
> > > > + * @hpd_state: number of data lanes available
> > >
> > > "number"?
> > >
> > > >   *
> > > >   * On some hardware a hotplug event notification may come from outside the display
> > > >   * driver / device. An example of this is some USB Type-C setups where the hardware
> > > > @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> > > >   * This function can be used to report these out-of-band events after obtaining
> > > >   * a drm_connector reference through calling drm_connector_find_by_fwnode().
> > > >   */
> > > > -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > > > +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> > > > +                                bool hpd_state)
> > >
> > > This is a boolean, how can it be a number?
> > >
> >
> > The kerneldoc wasn't appropriately updated as this went from being
> > "number of data lanes" to "the hot plug detect (hpd) state".
> >
> > > And having a "flag" like this is a pain, how do you know what the
> > > parameter really means?
> > >
> >
> > You're right, "state" isn't a boolean property, let's rename it
> > "hpd_high" to clarify it.
> 
> "connected" ?
> 

I've been trying to find some references to point to, but my
understanding is that in a DisplayPort or HDMI connector/cable you have
a dedicated HPD pin, which when high denotes the sink is alive _and_
EDID can be read.

So in a situation where you have a multifunction USB & DP/HDMI hub where
you connect a display, you might have the USB hub connected to the host
and you might even have your sink connected, but HPD could still be low
until the display is ready to talk to you. So physically everything is
connected, but this property will still be "not connected".

As such I don't think it's appropriate to name it "connected".

Regards,
Bjorn

> >
> > > >  {
> > > >     struct drm_connector *connector;
> > > >
> > > > @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > > >             return;
> > > >
> > > >     if (connector->funcs->oob_hotplug_event)
> > > > -           connector->funcs->oob_hotplug_event(connector);
> > > > +           connector->funcs->oob_hotplug_event(connector, hpd_state);
> > > >
> > > >     drm_connector_put(connector);
> > > >  }
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > > > index 146b83916005..00520867d37b 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > > > @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
> > > >     return intel_modeset_synced_crtcs(state, conn);
> > > >  }
> > > >
> > > > -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> > > > +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
> > > >  {
> > > >     struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
> > > >     struct drm_i915_private *i915 = to_i915(connector->dev);
> > > > +   bool need_work = false;
> > > >
> > > >     spin_lock_irq(&i915->irq_lock);
> > > > -   i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > > > +   if (hpd_state != i915->hotplug.oob_hotplug_state) {
> > > > +           i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > > > +
> > > > +           i915->hotplug.oob_hotplug_state = hpd_state;
> > > > +           need_work = true;
> > > > +   }
> > > >     spin_unlock_irq(&i915->irq_lock);
> > > > -   queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> > > > +
> > > > +   if (need_work)
> > > > +           queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> > > >  }
> > > >
> > > >  static const struct drm_connector_funcs intel_dp_connector_funcs = {
> > > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > > > index 8c1706fd81f9..543ebf1cfcf4 100644
> > > > --- a/drivers/gpu/drm/i915/i915_drv.h
> > > > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > > > @@ -149,6 +149,9 @@ struct i915_hotplug {
> > > >     /* Whether or not to count short HPD IRQs in HPD storms */
> > > >     u8 hpd_short_storm_enabled;
> > > >
> > > > +   /* Last state reported by oob_hotplug_event */
> > > > +   bool oob_hotplug_state;
> > > > +
> > > >     /*
> > > >      * if we get a HPD irq from DP and a HPD irq from non-DP
> > > >      * the non-DP HPD could block the workqueue on a mode config
> > > > diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> > > > index c1d8c23baa39..a4596be4d34a 100644
> > > > --- a/drivers/usb/typec/altmodes/displayport.c
> > > > +++ b/drivers/usb/typec/altmodes/displayport.c
> > > > @@ -59,7 +59,6 @@ struct dp_altmode {
> > > >     struct typec_displayport_data data;
> > > >
> > > >     enum dp_state state;
> > > > -   bool hpd;
> > > >
> > > >     struct mutex lock; /* device lock */
> > > >     struct work_struct work;
> > > > @@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
> > > >             if (!ret)
> > > >                     dp->state = DP_STATE_CONFIGURE;
> > > >     } else {
> > > > -           if (dp->hpd != hpd) {
> > > > -                   drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > > > -                   dp->hpd = hpd;
> > > > -           }
> > > > +           drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
> > > >     }
> > > >
> > > >     return ret;
> > > > @@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
> > > >     cancel_work_sync(&dp->work);
> > > >
> > > >     if (dp->connector_fwnode) {
> > > > -           if (dp->hpd)
> > > > -                   drm_connector_oob_hotplug_event(dp->connector_fwnode);
> > > > +           drm_connector_oob_hotplug_event(dp->connector_fwnode, false);
> > >
> > > See, what does "false" here mean?
> > >
> > > Name the function for what it does, do not have random flags as
> > > parameters, that makes it impossible to understand what the code is
> > > doing when you are reading it, without having to jump around and figure
> > > out what the flags are saying.
> > >
> > > And here they just don't even seem to be right :(
> > >
> >
> > Both the old and new code will signal to the DRM driver that the cable
> > was removed, the change is that we're carrying the level in the call
> > rather than just indicating that the state has changed.
> >
> > We could introduce some HPD_HIGH/HPD_LOW defines to make it easier to
> > read. But the various places I'm looking at just represented the hpd
> > state as a bool.
> >
> > Regards,
> > Bjorn
> 
> 
> 
> -- 
> With best wishes
> Dmitry

Re: [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Imre Deak]

On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> In some implementations, such as the Qualcomm platforms, the display
> driver has no way to query the current HPD state and as such it's
> impossible to distinguish between disconnect and attention events.
> 
> Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> state.
> 
> Also push the test for unchanged state in the displayport altmode driver
> into the i915 driver, to allow other drivers to act upon each update.
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
> 
> Note that the Intel driver has only been compile tested with this patch.
> 
>  drivers/gpu/drm/drm_connector.c          |  6 ++++--
>  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
>  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
>  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
>  include/drm/drm_connector.h              |  5 +++--
>  5 files changed, 23 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index a50c82bc2b2f..ad7295597c0f 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
>  /**
>   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
>   * @connector_fwnode: fwnode_handle to report the event on
> + * @hpd_state: number of data lanes available
>   *
>   * On some hardware a hotplug event notification may come from outside the display
>   * driver / device. An example of this is some USB Type-C setups where the hardware
> @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
>   * This function can be used to report these out-of-band events after obtaining
>   * a drm_connector reference through calling drm_connector_find_by_fwnode().
>   */
> -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> +				     bool hpd_state)
>  {
>  	struct drm_connector *connector;
>  
> @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
>  		return;
>  
>  	if (connector->funcs->oob_hotplug_event)
> -		connector->funcs->oob_hotplug_event(connector);
> +		connector->funcs->oob_hotplug_event(connector, hpd_state);
>  
>  	drm_connector_put(connector);
>  }
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 146b83916005..00520867d37b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
>  	return intel_modeset_synced_crtcs(state, conn);
>  }
>  
> -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
>  {
>  	struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
>  	struct drm_i915_private *i915 = to_i915(connector->dev);
> +	bool need_work = false;
>  
>  	spin_lock_irq(&i915->irq_lock);
> -	i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> +	if (hpd_state != i915->hotplug.oob_hotplug_state) {

hpd_state is speific to the encoder (pin) so similarly to event_bits
oob_hotplug_state should be a bitmask as well.

> +		i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> +
> +		i915->hotplug.oob_hotplug_state = hpd_state;
> +		need_work = true;
> +	}
>  	spin_unlock_irq(&i915->irq_lock);
> -	queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> +
> +	if (need_work)
> +		queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
>  }
>  
>  static const struct drm_connector_funcs intel_dp_connector_funcs = {
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 8c1706fd81f9..543ebf1cfcf4 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -149,6 +149,9 @@ struct i915_hotplug {
>  	/* Whether or not to count short HPD IRQs in HPD storms */
>  	u8 hpd_short_storm_enabled;
>  
> +	/* Last state reported by oob_hotplug_event */
> +	bool oob_hotplug_state;
> +
>  	/*
>  	 * if we get a HPD irq from DP and a HPD irq from non-DP
>  	 * the non-DP HPD could block the workqueue on a mode config
> diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> index c1d8c23baa39..a4596be4d34a 100644
> --- a/drivers/usb/typec/altmodes/displayport.c
> +++ b/drivers/usb/typec/altmodes/displayport.c
> @@ -59,7 +59,6 @@ struct dp_altmode {
>  	struct typec_displayport_data data;
>  
>  	enum dp_state state;
> -	bool hpd;
>  
>  	struct mutex lock; /* device lock */
>  	struct work_struct work;
> @@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
>  		if (!ret)
>  			dp->state = DP_STATE_CONFIGURE;
>  	} else {
> -		if (dp->hpd != hpd) {
> -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> -			dp->hpd = hpd;
> -		}
> +		drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
>  	}
>  
>  	return ret;
> @@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
>  	cancel_work_sync(&dp->work);
>  
>  	if (dp->connector_fwnode) {
> -		if (dp->hpd)
> -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> +		drm_connector_oob_hotplug_event(dp->connector_fwnode, false);
>  
>  		fwnode_handle_put(dp->connector_fwnode);
>  	}
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 64cf5f88c05b..7c90b8eb2ace 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -1141,7 +1141,7 @@ struct drm_connector_funcs {
>  	 * This will get called when a hotplug-event for a drm-connector
>  	 * has been received from a source outside the display driver / device.
>  	 */
> -	void (*oob_hotplug_event)(struct drm_connector *connector);
> +	void (*oob_hotplug_event)(struct drm_connector *connector, bool hpd_state);
>  };
>  
>  /**
> @@ -1742,7 +1742,8 @@ drm_connector_is_unregistered(struct drm_connector *connector)
>  		DRM_CONNECTOR_UNREGISTERED;
>  }
>  
> -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode);
> +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> +				     bool hpd_state);
>  const char *drm_get_connector_type_name(unsigned int connector_type);
>  const char *drm_get_connector_status_name(enum drm_connector_status status);
>  const char *drm_get_subpixel_order_name(enum subpixel_order order);
> -- 
> 2.33.1
> 

Re: [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Imre Deak]

On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> In some implementations, such as the Qualcomm platforms, the display
> driver has no way to query the current HPD state and as such it's
> impossible to distinguish between disconnect and attention events.
> 
> Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> state.
> 
> Also push the test for unchanged state in the displayport altmode driver
> into the i915 driver, to allow other drivers to act upon each update.
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
> 
> Note that the Intel driver has only been compile tested with this patch.
> 
>  drivers/gpu/drm/drm_connector.c          |  6 ++++--
>  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
>  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
>  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
>  include/drm/drm_connector.h              |  5 +++--
>  5 files changed, 23 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index a50c82bc2b2f..ad7295597c0f 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
>  /**
>   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
>   * @connector_fwnode: fwnode_handle to report the event on
> + * @hpd_state: number of data lanes available
>   *
>   * On some hardware a hotplug event notification may come from outside the display
>   * driver / device. An example of this is some USB Type-C setups where the hardware
> @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
>   * This function can be used to report these out-of-band events after obtaining
>   * a drm_connector reference through calling drm_connector_find_by_fwnode().
>   */
> -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> +				     bool hpd_state)
>  {
>  	struct drm_connector *connector;
>  
> @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
>  		return;
>  
>  	if (connector->funcs->oob_hotplug_event)
> -		connector->funcs->oob_hotplug_event(connector);
> +		connector->funcs->oob_hotplug_event(connector, hpd_state);
>  
>  	drm_connector_put(connector);
>  }
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 146b83916005..00520867d37b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
>  	return intel_modeset_synced_crtcs(state, conn);
>  }
>  
> -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
>  {
>  	struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
>  	struct drm_i915_private *i915 = to_i915(connector->dev);
> +	bool need_work = false;
>  
>  	spin_lock_irq(&i915->irq_lock);
> -	i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> +	if (hpd_state != i915->hotplug.oob_hotplug_state) {

hpd_state is speific to the encoder (pin) so similarly to event_bits
oob_hotplug_state should be a bitmask as well.

> +		i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> +
> +		i915->hotplug.oob_hotplug_state = hpd_state;
> +		need_work = true;
> +	}
>  	spin_unlock_irq(&i915->irq_lock);
> -	queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> +
> +	if (need_work)
> +		queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
>  }
>  
>  static const struct drm_connector_funcs intel_dp_connector_funcs = {
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 8c1706fd81f9..543ebf1cfcf4 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -149,6 +149,9 @@ struct i915_hotplug {
>  	/* Whether or not to count short HPD IRQs in HPD storms */
>  	u8 hpd_short_storm_enabled;
>  
> +	/* Last state reported by oob_hotplug_event */
> +	bool oob_hotplug_state;
> +
>  	/*
>  	 * if we get a HPD irq from DP and a HPD irq from non-DP
>  	 * the non-DP HPD could block the workqueue on a mode config
> diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> index c1d8c23baa39..a4596be4d34a 100644
> --- a/drivers/usb/typec/altmodes/displayport.c
> +++ b/drivers/usb/typec/altmodes/displayport.c
> @@ -59,7 +59,6 @@ struct dp_altmode {
>  	struct typec_displayport_data data;
>  
>  	enum dp_state state;
> -	bool hpd;
>  
>  	struct mutex lock; /* device lock */
>  	struct work_struct work;
> @@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
>  		if (!ret)
>  			dp->state = DP_STATE_CONFIGURE;
>  	} else {
> -		if (dp->hpd != hpd) {
> -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> -			dp->hpd = hpd;
> -		}
> +		drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
>  	}
>  
>  	return ret;
> @@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
>  	cancel_work_sync(&dp->work);
>  
>  	if (dp->connector_fwnode) {
> -		if (dp->hpd)
> -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> +		drm_connector_oob_hotplug_event(dp->connector_fwnode, false);
>  
>  		fwnode_handle_put(dp->connector_fwnode);
>  	}
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 64cf5f88c05b..7c90b8eb2ace 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -1141,7 +1141,7 @@ struct drm_connector_funcs {
>  	 * This will get called when a hotplug-event for a drm-connector
>  	 * has been received from a source outside the display driver / device.
>  	 */
> -	void (*oob_hotplug_event)(struct drm_connector *connector);
> +	void (*oob_hotplug_event)(struct drm_connector *connector, bool hpd_state);
>  };
>  
>  /**
> @@ -1742,7 +1742,8 @@ drm_connector_is_unregistered(struct drm_connector *connector)
>  		DRM_CONNECTOR_UNREGISTERED;
>  }
>  
> -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode);
> +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> +				     bool hpd_state);
>  const char *drm_get_connector_type_name(unsigned int connector_type);
>  const char *drm_get_connector_status_name(enum drm_connector_status status);
>  const char *drm_get_subpixel_order_name(enum subpixel_order order);
> -- 
> 2.33.1
> 

Re: [Intel-gfx] [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Imre Deak]

On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> In some implementations, such as the Qualcomm platforms, the display
> driver has no way to query the current HPD state and as such it's
> impossible to distinguish between disconnect and attention events.
> 
> Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> state.
> 
> Also push the test for unchanged state in the displayport altmode driver
> into the i915 driver, to allow other drivers to act upon each update.
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
> 
> Note that the Intel driver has only been compile tested with this patch.
> 
>  drivers/gpu/drm/drm_connector.c          |  6 ++++--
>  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
>  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
>  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
>  include/drm/drm_connector.h              |  5 +++--
>  5 files changed, 23 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index a50c82bc2b2f..ad7295597c0f 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
>  /**
>   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
>   * @connector_fwnode: fwnode_handle to report the event on
> + * @hpd_state: number of data lanes available
>   *
>   * On some hardware a hotplug event notification may come from outside the display
>   * driver / device. An example of this is some USB Type-C setups where the hardware
> @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
>   * This function can be used to report these out-of-band events after obtaining
>   * a drm_connector reference through calling drm_connector_find_by_fwnode().
>   */
> -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> +				     bool hpd_state)
>  {
>  	struct drm_connector *connector;
>  
> @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
>  		return;
>  
>  	if (connector->funcs->oob_hotplug_event)
> -		connector->funcs->oob_hotplug_event(connector);
> +		connector->funcs->oob_hotplug_event(connector, hpd_state);
>  
>  	drm_connector_put(connector);
>  }
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 146b83916005..00520867d37b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
>  	return intel_modeset_synced_crtcs(state, conn);
>  }
>  
> -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
>  {
>  	struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
>  	struct drm_i915_private *i915 = to_i915(connector->dev);
> +	bool need_work = false;
>  
>  	spin_lock_irq(&i915->irq_lock);
> -	i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> +	if (hpd_state != i915->hotplug.oob_hotplug_state) {

hpd_state is speific to the encoder (pin) so similarly to event_bits
oob_hotplug_state should be a bitmask as well.

> +		i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> +
> +		i915->hotplug.oob_hotplug_state = hpd_state;
> +		need_work = true;
> +	}
>  	spin_unlock_irq(&i915->irq_lock);
> -	queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
> +
> +	if (need_work)
> +		queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
>  }
>  
>  static const struct drm_connector_funcs intel_dp_connector_funcs = {
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 8c1706fd81f9..543ebf1cfcf4 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -149,6 +149,9 @@ struct i915_hotplug {
>  	/* Whether or not to count short HPD IRQs in HPD storms */
>  	u8 hpd_short_storm_enabled;
>  
> +	/* Last state reported by oob_hotplug_event */
> +	bool oob_hotplug_state;
> +
>  	/*
>  	 * if we get a HPD irq from DP and a HPD irq from non-DP
>  	 * the non-DP HPD could block the workqueue on a mode config
> diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> index c1d8c23baa39..a4596be4d34a 100644
> --- a/drivers/usb/typec/altmodes/displayport.c
> +++ b/drivers/usb/typec/altmodes/displayport.c
> @@ -59,7 +59,6 @@ struct dp_altmode {
>  	struct typec_displayport_data data;
>  
>  	enum dp_state state;
> -	bool hpd;
>  
>  	struct mutex lock; /* device lock */
>  	struct work_struct work;
> @@ -143,10 +142,7 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
>  		if (!ret)
>  			dp->state = DP_STATE_CONFIGURE;
>  	} else {
> -		if (dp->hpd != hpd) {
> -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> -			dp->hpd = hpd;
> -		}
> +		drm_connector_oob_hotplug_event(dp->connector_fwnode, hpd);
>  	}
>  
>  	return ret;
> @@ -573,8 +569,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
>  	cancel_work_sync(&dp->work);
>  
>  	if (dp->connector_fwnode) {
> -		if (dp->hpd)
> -			drm_connector_oob_hotplug_event(dp->connector_fwnode);
> +		drm_connector_oob_hotplug_event(dp->connector_fwnode, false);
>  
>  		fwnode_handle_put(dp->connector_fwnode);
>  	}
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 64cf5f88c05b..7c90b8eb2ace 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -1141,7 +1141,7 @@ struct drm_connector_funcs {
>  	 * This will get called when a hotplug-event for a drm-connector
>  	 * has been received from a source outside the display driver / device.
>  	 */
> -	void (*oob_hotplug_event)(struct drm_connector *connector);
> +	void (*oob_hotplug_event)(struct drm_connector *connector, bool hpd_state);
>  };
>  
>  /**
> @@ -1742,7 +1742,8 @@ drm_connector_is_unregistered(struct drm_connector *connector)
>  		DRM_CONNECTOR_UNREGISTERED;
>  }
>  
> -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode);
> +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> +				     bool hpd_state);
>  const char *drm_get_connector_type_name(unsigned int connector_type);
>  const char *drm_get_connector_status_name(enum drm_connector_status status);
>  const char *drm_get_subpixel_order_name(enum subpixel_order order);
> -- 
> 2.33.1
> 

Re: [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Bjorn Andersson]

On Mon 14 Feb 09:59 PST 2022, Imre Deak wrote:

> On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> > In some implementations, such as the Qualcomm platforms, the display
> > driver has no way to query the current HPD state and as such it's
> > impossible to distinguish between disconnect and attention events.
> > 
> > Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> > state.
> > 
> > Also push the test for unchanged state in the displayport altmode driver
> > into the i915 driver, to allow other drivers to act upon each update.
> > 
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > ---
> > 
> > Note that the Intel driver has only been compile tested with this patch.
> > 
> >  drivers/gpu/drm/drm_connector.c          |  6 ++++--
> >  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
> >  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
> >  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
> >  include/drm/drm_connector.h              |  5 +++--
> >  5 files changed, 23 insertions(+), 14 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> > index a50c82bc2b2f..ad7295597c0f 100644
> > --- a/drivers/gpu/drm/drm_connector.c
> > +++ b/drivers/gpu/drm/drm_connector.c
> > @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> >  /**
> >   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
> >   * @connector_fwnode: fwnode_handle to report the event on
> > + * @hpd_state: number of data lanes available
> >   *
> >   * On some hardware a hotplug event notification may come from outside the display
> >   * driver / device. An example of this is some USB Type-C setups where the hardware
> > @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> >   * This function can be used to report these out-of-band events after obtaining
> >   * a drm_connector reference through calling drm_connector_find_by_fwnode().
> >   */
> > -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> > +				     bool hpd_state)
> >  {
> >  	struct drm_connector *connector;
> >  
> > @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> >  		return;
> >  
> >  	if (connector->funcs->oob_hotplug_event)
> > -		connector->funcs->oob_hotplug_event(connector);
> > +		connector->funcs->oob_hotplug_event(connector, hpd_state);
> >  
> >  	drm_connector_put(connector);
> >  }
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > index 146b83916005..00520867d37b 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
> >  	return intel_modeset_synced_crtcs(state, conn);
> >  }
> >  
> > -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> > +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
> >  {
> >  	struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
> >  	struct drm_i915_private *i915 = to_i915(connector->dev);
> > +	bool need_work = false;
> >  
> >  	spin_lock_irq(&i915->irq_lock);
> > -	i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > +	if (hpd_state != i915->hotplug.oob_hotplug_state) {
> 
> hpd_state is speific to the encoder (pin) so similarly to event_bits
> oob_hotplug_state should be a bitmask as well.
> 

That makes sense, thanks for point it out!

Regards,
Bjorn

Re: [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Bjorn Andersson]

On Mon 14 Feb 09:59 PST 2022, Imre Deak wrote:

> On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> > In some implementations, such as the Qualcomm platforms, the display
> > driver has no way to query the current HPD state and as such it's
> > impossible to distinguish between disconnect and attention events.
> > 
> > Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> > state.
> > 
> > Also push the test for unchanged state in the displayport altmode driver
> > into the i915 driver, to allow other drivers to act upon each update.
> > 
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > ---
> > 
> > Note that the Intel driver has only been compile tested with this patch.
> > 
> >  drivers/gpu/drm/drm_connector.c          |  6 ++++--
> >  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
> >  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
> >  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
> >  include/drm/drm_connector.h              |  5 +++--
> >  5 files changed, 23 insertions(+), 14 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> > index a50c82bc2b2f..ad7295597c0f 100644
> > --- a/drivers/gpu/drm/drm_connector.c
> > +++ b/drivers/gpu/drm/drm_connector.c
> > @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> >  /**
> >   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
> >   * @connector_fwnode: fwnode_handle to report the event on
> > + * @hpd_state: number of data lanes available
> >   *
> >   * On some hardware a hotplug event notification may come from outside the display
> >   * driver / device. An example of this is some USB Type-C setups where the hardware
> > @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> >   * This function can be used to report these out-of-band events after obtaining
> >   * a drm_connector reference through calling drm_connector_find_by_fwnode().
> >   */
> > -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> > +				     bool hpd_state)
> >  {
> >  	struct drm_connector *connector;
> >  
> > @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> >  		return;
> >  
> >  	if (connector->funcs->oob_hotplug_event)
> > -		connector->funcs->oob_hotplug_event(connector);
> > +		connector->funcs->oob_hotplug_event(connector, hpd_state);
> >  
> >  	drm_connector_put(connector);
> >  }
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > index 146b83916005..00520867d37b 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
> >  	return intel_modeset_synced_crtcs(state, conn);
> >  }
> >  
> > -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> > +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
> >  {
> >  	struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
> >  	struct drm_i915_private *i915 = to_i915(connector->dev);
> > +	bool need_work = false;
> >  
> >  	spin_lock_irq(&i915->irq_lock);
> > -	i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > +	if (hpd_state != i915->hotplug.oob_hotplug_state) {
> 
> hpd_state is speific to the encoder (pin) so similarly to event_bits
> oob_hotplug_state should be a bitmask as well.
> 

That makes sense, thanks for point it out!

Regards,
Bjorn

Re: [Intel-gfx] [PATCH 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Bjorn Andersson]

On Mon 14 Feb 09:59 PST 2022, Imre Deak wrote:

> On Mon, Feb 07, 2022 at 08:43:27PM -0800, Bjorn Andersson wrote:
> > In some implementations, such as the Qualcomm platforms, the display
> > driver has no way to query the current HPD state and as such it's
> > impossible to distinguish between disconnect and attention events.
> > 
> > Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
> > state.
> > 
> > Also push the test for unchanged state in the displayport altmode driver
> > into the i915 driver, to allow other drivers to act upon each update.
> > 
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > ---
> > 
> > Note that the Intel driver has only been compile tested with this patch.
> > 
> >  drivers/gpu/drm/drm_connector.c          |  6 ++++--
> >  drivers/gpu/drm/i915/display/intel_dp.c  | 14 +++++++++++---
> >  drivers/gpu/drm/i915/i915_drv.h          |  3 +++
> >  drivers/usb/typec/altmodes/displayport.c |  9 ++-------
> >  include/drm/drm_connector.h              |  5 +++--
> >  5 files changed, 23 insertions(+), 14 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> > index a50c82bc2b2f..ad7295597c0f 100644
> > --- a/drivers/gpu/drm/drm_connector.c
> > +++ b/drivers/gpu/drm/drm_connector.c
> > @@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> >  /**
> >   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
> >   * @connector_fwnode: fwnode_handle to report the event on
> > + * @hpd_state: number of data lanes available
> >   *
> >   * On some hardware a hotplug event notification may come from outside the display
> >   * driver / device. An example of this is some USB Type-C setups where the hardware
> > @@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> >   * This function can be used to report these out-of-band events after obtaining
> >   * a drm_connector reference through calling drm_connector_find_by_fwnode().
> >   */
> > -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> > +void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> > +				     bool hpd_state)
> >  {
> >  	struct drm_connector *connector;
> >  
> > @@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
> >  		return;
> >  
> >  	if (connector->funcs->oob_hotplug_event)
> > -		connector->funcs->oob_hotplug_event(connector);
> > +		connector->funcs->oob_hotplug_event(connector, hpd_state);
> >  
> >  	drm_connector_put(connector);
> >  }
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > index 146b83916005..00520867d37b 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -4816,15 +4816,23 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
> >  	return intel_modeset_synced_crtcs(state, conn);
> >  }
> >  
> > -static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
> > +static void intel_dp_oob_hotplug_event(struct drm_connector *connector, bool hpd_state)
> >  {
> >  	struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
> >  	struct drm_i915_private *i915 = to_i915(connector->dev);
> > +	bool need_work = false;
> >  
> >  	spin_lock_irq(&i915->irq_lock);
> > -	i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
> > +	if (hpd_state != i915->hotplug.oob_hotplug_state) {
> 
> hpd_state is speific to the encoder (pin) so similarly to event_bits
> oob_hotplug_state should be a bitmask as well.
> 

That makes sense, thanks for point it out!

Regards,
Bjorn