diff mbox series

[v5,1/2] drm: Add detection of changing of edid on between suspend and resume

Message ID 20190411143632.26838-2-gwan-gyeong.mun@intel.com (mailing list archive)
State New, archived
Headers show
Series drm: Add detection of changing of edid on between suspend and resume | expand

Commit Message

Gwan-gyeong Mun April 11, 2019, 2:36 p.m. UTC
The hotplug detection routine of drm_helper_hpd_irq_event() can detect
changing of status of connector, but it can not detect changing of edid.

Following scenario requires detection of changing of edid.

 1) plug display device to a connector
 2) system suspend
 3) unplug 1)'s display device and plug the other display device to a
    connector
 4) system resume

It adds edid check routine when a connector status still remains as
"connector_status_connected".

v2: Add NULL check before comparing of EDIDs.
v3: Make it as part of existing drm_helper_hpd_irq_event() (Stan, Mika)
v4: Rebased
v5: Use a cached edid property blob data of connector instead of adding
    a new detected_edid variable. (Maarten)
    Add an using of reference count for getting a cached edid property
    blob data. (Maarten)

Testcase: igt/kms_chamelium/hdmi-edid-change-during-hibernate
Testcase: igt/kms_chamelium/hdmi-edid-change-during-suspend
Testcase: igt/kms_chamelium/dp-edid-change-during-hibernate
Testcase: igt/kms_chamelium/dp-edid-change-during-suspend

Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
---
 drivers/gpu/drm/drm_probe_helper.c | 34 +++++++++++++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

Comments

Stanislav Lisovskiy April 11, 2019, 4 p.m. UTC | #1
On Thu, 2019-04-11 at 17:36 +0300, Gwan-gyeong Mun wrote:
> The hotplug detection routine of drm_helper_hpd_irq_event() can
> detect
> changing of status of connector, but it can not detect changing of
> edid.
> 
> Following scenario requires detection of changing of edid.
> 
>  1) plug display device to a connector
>  2) system suspend
>  3) unplug 1)'s display device and plug the other display device to a
>     connector
>  4) system resume
> 
> It adds edid check routine when a connector status still remains as
> "connector_status_connected".
> 
> v2: Add NULL check before comparing of EDIDs.
> v3: Make it as part of existing drm_helper_hpd_irq_event() (Stan,
> Mika)
> v4: Rebased
> v5: Use a cached edid property blob data of connector instead of
> adding
>     a new detected_edid variable. (Maarten)
>     Add an using of reference count for getting a cached edid
> property
>     blob data. (Maarten)
> 
> Testcase: igt/kms_chamelium/hdmi-edid-change-during-hibernate
> Testcase: igt/kms_chamelium/hdmi-edid-change-during-suspend
> Testcase: igt/kms_chamelium/dp-edid-change-during-hibernate
> Testcase: igt/kms_chamelium/dp-edid-change-during-suspend
> 
> Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
> ---
>  drivers/gpu/drm/drm_probe_helper.c | 34
> +++++++++++++++++++++++++++++-
>  1 file changed, 33 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_probe_helper.c
> b/drivers/gpu/drm/drm_probe_helper.c
> index 6fd08e04b323..27ad7f3dabb7 100644
> --- a/drivers/gpu/drm/drm_probe_helper.c
> +++ b/drivers/gpu/drm/drm_probe_helper.c
> @@ -742,7 +742,16 @@ EXPORT_SYMBOL(drm_kms_helper_poll_fini);
>   * panels.
>   *
>   * This helper function is useful for drivers which can't or don't
> track hotplug
> - * interrupts for each connector.
> + * interrupts for each connector. And it also supports a detection
> of changing
> + * of edid on between suspend and resume when a connector status
> still remains
> + * as "connector_status_connected".
> + *
> + * Following scenario requires detection of changing of edid.
> + *  1) plug display device to a connector
> + *  2) system suspend
> + *  3) unplug 1)'s display device and plug the other display device
> to a
> + *     connector
> + *  4) system resume
>   *
>   * Drivers which support hotplug interrupts for each connector
> individually and
>   * which have a more fine-grained detect logic should bypass this
> code and
> @@ -760,6 +769,7 @@ bool drm_helper_hpd_irq_event(struct drm_device
> *dev)
>  	struct drm_connector *connector;
>  	struct drm_connector_list_iter conn_iter;
>  	enum drm_connector_status old_status;
> +	struct drm_property_blob *old_edid_blob_ptr;
>  	bool changed = false;
>  
>  	if (!dev->mode_config.poll_enabled)
> @@ -774,6 +784,11 @@ bool drm_helper_hpd_irq_event(struct drm_device
> *dev)
>  
>  		old_status = connector->status;
>  
> +		if (connector->edid_blob_ptr)
> +			old_edid_blob_ptr =
> drm_property_blob_get(connector->edid_blob_ptr);
> +		else
> +			old_edid_blob_ptr = NULL;
> +
>  		connector->status = drm_helper_probe_detect(connector,
> NULL, false);
>  		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s
> to %s\n",
>  			      connector->base.id,
> @@ -782,6 +797,23 @@ bool drm_helper_hpd_irq_event(struct drm_device
> *dev)
>  			      drm_get_connector_status_name(connector-
> >status));
>  		if (old_status != connector->status)
>  			changed = true;
> +
> +		/* Check changing of edid when a connector status still
> remains
> +		 * as "connector_status_connected".
> +		 */
> +		if (old_edid_blob_ptr && connector->edid_blob_ptr &&

I guess you don't need to check both old_edid_blob_ptr && connector-
>edid_blob_ptr here. Because if old_edid_blob_ptr is not NULL - it
means that connector->edid_blob_ptr was not NULL for sure. See the 
condition you have added above.
I mean this one:

> +		if (connector->edid_blob_ptr)
> +			old_edid_blob_ptr =
> drm_property_blob_get(connector->edid_blob_ptr);
> +		else
> +			old_edid_blob_ptr = NULL;

So I would check only old_edid_blob_ptr for not being NULL here.



> +		    old_status == connector->status &&
> +		    old_status == connector_status_connected) {
> +			if (memcmp(old_edid_blob_ptr->data,
> +				connector->edid_blob_ptr->data,
> +				old_edid_blob_ptr->length)) {
> +				changed = true;
> +				DRM_DEBUG_KMS("[CONNECTOR:%d:%s] edid
> updated\n",
> +					      connector->base.id,
> +					      connector->name);
> +			}
> +		}
> +		drm_property_blob_put(old_edid_blob_ptr);
>  	}
>  	drm_connector_list_iter_end(&conn_iter);
>  	mutex_unlock(&dev->mode_config.mutex);
Gwan-gyeong Mun April 16, 2019, 1:55 p.m. UTC | #2
On Thu, 2019-04-11 at 17:00 +0100, Lisovskiy, Stanislav wrote:
> On Thu, 2019-04-11 at 17:36 +0300, Gwan-gyeong Mun wrote:
> > The hotplug detection routine of drm_helper_hpd_irq_event() can
> > detect
> > changing of status of connector, but it can not detect changing of
> > edid.
> > 
> > Following scenario requires detection of changing of edid.
> > 
> >  1) plug display device to a connector
> >  2) system suspend
> >  3) unplug 1)'s display device and plug the other display device to
> > a
> >     connector
> >  4) system resume
> > 
> > It adds edid check routine when a connector status still remains as
> > "connector_status_connected".
> > 
> > v2: Add NULL check before comparing of EDIDs.
> > v3: Make it as part of existing drm_helper_hpd_irq_event() (Stan,
> > Mika)
> > v4: Rebased
> > v5: Use a cached edid property blob data of connector instead of
> > adding
> >     a new detected_edid variable. (Maarten)
> >     Add an using of reference count for getting a cached edid
> > property
> >     blob data. (Maarten)
> > 
> > Testcase: igt/kms_chamelium/hdmi-edid-change-during-hibernate
> > Testcase: igt/kms_chamelium/hdmi-edid-change-during-suspend
> > Testcase: igt/kms_chamelium/dp-edid-change-during-hibernate
> > Testcase: igt/kms_chamelium/dp-edid-change-during-suspend
> > 
> > Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
> > ---
> >  drivers/gpu/drm/drm_probe_helper.c | 34
> > +++++++++++++++++++++++++++++-
> >  1 file changed, 33 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_probe_helper.c
> > b/drivers/gpu/drm/drm_probe_helper.c
> > index 6fd08e04b323..27ad7f3dabb7 100644
> > --- a/drivers/gpu/drm/drm_probe_helper.c
> > +++ b/drivers/gpu/drm/drm_probe_helper.c
> > @@ -742,7 +742,16 @@ EXPORT_SYMBOL(drm_kms_helper_poll_fini);
> >   * panels.
> >   *
> >   * This helper function is useful for drivers which can't or don't
> > track hotplug
> > - * interrupts for each connector.
> > + * interrupts for each connector. And it also supports a detection
> > of changing
> > + * of edid on between suspend and resume when a connector status
> > still remains
> > + * as "connector_status_connected".
> > + *
> > + * Following scenario requires detection of changing of edid.
> > + *  1) plug display device to a connector
> > + *  2) system suspend
> > + *  3) unplug 1)'s display device and plug the other display
> > device
> > to a
> > + *     connector
> > + *  4) system resume
> >   *
> >   * Drivers which support hotplug interrupts for each connector
> > individually and
> >   * which have a more fine-grained detect logic should bypass this
> > code and
> > @@ -760,6 +769,7 @@ bool drm_helper_hpd_irq_event(struct drm_device
> > *dev)
> >  	struct drm_connector *connector;
> >  	struct drm_connector_list_iter conn_iter;
> >  	enum drm_connector_status old_status;
> > +	struct drm_property_blob *old_edid_blob_ptr;
> >  	bool changed = false;
> >  
> >  	if (!dev->mode_config.poll_enabled)
> > @@ -774,6 +784,11 @@ bool drm_helper_hpd_irq_event(struct
> > drm_device
> > *dev)
> >  
> >  		old_status = connector->status;
> >  
> > +		if (connector->edid_blob_ptr)
> > +			old_edid_blob_ptr =
> > drm_property_blob_get(connector->edid_blob_ptr);
> > +		else
> > +			old_edid_blob_ptr = NULL;
> > +
> >  		connector->status = drm_helper_probe_detect(connector,
> > NULL, false);
> >  		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s
> > to %s\n",
> >  			      connector->base.id,
> > @@ -782,6 +797,23 @@ bool drm_helper_hpd_irq_event(struct
> > drm_device
> > *dev)
> >  			      drm_get_connector_status_name(connector-
> > > status));
> >  		if (old_status != connector->status)
> >  			changed = true;
> > +
> > +		/* Check changing of edid when a connector status still
> > remains
> > +		 * as "connector_status_connected".
> > +		 */
> > +		if (old_edid_blob_ptr && connector->edid_blob_ptr &&
> 
> I guess you don't need to check both old_edid_blob_ptr && connector-
> > edid_blob_ptr here. Because if old_edid_blob_ptr is not NULL - it
> means that connector->edid_blob_ptr was not NULL for sure. See the 
> condition you have added above.
> I mean this one:
> 
> > +		if (connector->edid_blob_ptr)
> > +			old_edid_blob_ptr =
> > drm_property_blob_get(connector->edid_blob_ptr);
> > +		else
> > +			old_edid_blob_ptr = NULL;
> 
> So I would check only old_edid_blob_ptr for not being NULL here.
> 
> 
Hi Stan,

Thank you for checking it.

First, drivers could set edid_blob_ptr to NULL with
drm_connector_update_edid_property().
And drm_helper_probe_detect() could lead updating of an internal edid
of driver and if driver can not get EDID from I2C, it could call
drm_connector_update_edid_property() with NULL.

therefore I think that we should check old and new edid_blob_ptr are
NULL or not.
> 
> > +		    old_status == connector->status &&
> > +		    old_status == connector_status_connected) {
> > +			if (memcmp(old_edid_blob_ptr->data,
> > +				connector->edid_blob_ptr->data,
> > +				old_edid_blob_ptr->length)) {
> > +				changed = true;
> > +				DRM_DEBUG_KMS("[CONNECTOR:%d:%s] edid
> > updated\n",
> > +					      connector->base.id,
> > +					      connector->name);
> > +			}
> > +		}
> > +		drm_property_blob_put(old_edid_blob_ptr);
> >  	}
> >  	drm_connector_list_iter_end(&conn_iter);
> >  	mutex_unlock(&dev->mode_config.mutex);
diff mbox series

Patch

diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
index 6fd08e04b323..27ad7f3dabb7 100644
--- a/drivers/gpu/drm/drm_probe_helper.c
+++ b/drivers/gpu/drm/drm_probe_helper.c
@@ -742,7 +742,16 @@  EXPORT_SYMBOL(drm_kms_helper_poll_fini);
  * panels.
  *
  * This helper function is useful for drivers which can't or don't track hotplug
- * interrupts for each connector.
+ * interrupts for each connector. And it also supports a detection of changing
+ * of edid on between suspend and resume when a connector status still remains
+ * as "connector_status_connected".
+ *
+ * Following scenario requires detection of changing of edid.
+ *  1) plug display device to a connector
+ *  2) system suspend
+ *  3) unplug 1)'s display device and plug the other display device to a
+ *     connector
+ *  4) system resume
  *
  * Drivers which support hotplug interrupts for each connector individually and
  * which have a more fine-grained detect logic should bypass this code and
@@ -760,6 +769,7 @@  bool drm_helper_hpd_irq_event(struct drm_device *dev)
 	struct drm_connector *connector;
 	struct drm_connector_list_iter conn_iter;
 	enum drm_connector_status old_status;
+	struct drm_property_blob *old_edid_blob_ptr;
 	bool changed = false;
 
 	if (!dev->mode_config.poll_enabled)
@@ -774,6 +784,11 @@  bool drm_helper_hpd_irq_event(struct drm_device *dev)
 
 		old_status = connector->status;
 
+		if (connector->edid_blob_ptr)
+			old_edid_blob_ptr = drm_property_blob_get(connector->edid_blob_ptr);
+		else
+			old_edid_blob_ptr = NULL;
+
 		connector->status = drm_helper_probe_detect(connector, NULL, false);
 		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
 			      connector->base.id,
@@ -782,6 +797,23 @@  bool drm_helper_hpd_irq_event(struct drm_device *dev)
 			      drm_get_connector_status_name(connector->status));
 		if (old_status != connector->status)
 			changed = true;
+
+		/* Check changing of edid when a connector status still remains
+		 * as "connector_status_connected".
+		 */
+		if (old_edid_blob_ptr && connector->edid_blob_ptr &&
+		    old_status == connector->status &&
+		    old_status == connector_status_connected) {
+			if (memcmp(old_edid_blob_ptr->data,
+				connector->edid_blob_ptr->data,
+				old_edid_blob_ptr->length)) {
+				changed = true;
+				DRM_DEBUG_KMS("[CONNECTOR:%d:%s] edid updated\n",
+					      connector->base.id,
+					      connector->name);
+			}
+		}
+		drm_property_blob_put(old_edid_blob_ptr);
 	}
 	drm_connector_list_iter_end(&conn_iter);
 	mutex_unlock(&dev->mode_config.mutex);