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)
v6: Fixes coding style.
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@xxxxxxxxx>
---
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..da8aff116ca4 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);
--
2.21.0
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