The hotplug detection routine of i915 uses drm_helper_hpd_irq_event(). This
helper 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.
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/i915/intel_hotplug.c | 83 +++++++++++++++++++++++++++-
1 file changed, 82 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c
index 648a13c6043c..0bd3e1c38167 100644
--- a/drivers/gpu/drm/i915/intel_hotplug.c
+++ b/drivers/gpu/drm/i915/intel_hotplug.c
@@ -507,6 +507,87 @@ void intel_hpd_init(struct drm_i915_private *dev_priv)
}
}
+/**
+ * intel_hpd_irq_event - hotplug processing
+ * @dev: drm_device
+ *
+ * Drivers can use this function to run a detect cycle on all connectors which
+ * have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All other
+ * connectors are ignored, which is useful to avoid reprobing fixed panels.
+ *
+ * This function is useful for drivers which can't or don't track hotplug interrupts
+ * for each connector. This function is based on drm_helper_hpd_irq_event() helper
+ * function and besides it adds edid check routine 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
+
+ * This function must be called from process context with no mode
+ * setting locks held.
+ *
+ * Note that a connector can be both polled and probed from the hotplug handler,
+ * in case the hotplug interrupt is known to be unreliable.
+ */
+static bool intel_hpd_irq_event(struct drm_device *dev)
+{
+ struct drm_connector *connector;
+ struct drm_connector_list_iter conn_iter;
+ enum drm_connector_status old_status, cur_status;
+ struct edid *old_edid;
+ bool changed = false;
+
+ if (!dev->mode_config.poll_enabled)
+ return false;
+
+ mutex_lock(&dev->mode_config.mutex);
+ drm_connector_list_iter_begin(dev, &conn_iter);
+ drm_for_each_connector_iter(connector, &conn_iter) {
+ /* Only handle HPD capable connectors. */
+ if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
+ continue;
+
+ old_status = connector->status;
+ old_edid = to_intel_connector(connector)->detect_edid;
+
+ cur_status = drm_helper_probe_detect(connector, NULL, false);
+ DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
+ connector->base.id, connector->name,
+ drm_get_connector_status_name(old_status),
+ drm_get_connector_status_name(cur_status));
+
+ if (old_status != cur_status)
+ changed = true;
+
+ /* Check changing of edid when a connector status still remains
+ * as "connector_status_connected".
+ */
+ if (old_status == cur_status &&
+ cur_status == connector_status_connected) {
+ struct edid *cur_edid = to_intel_connector(connector)->detect_edid;
+ if (!old_edid || !cur_edid)
+ continue;
+
+ if (memcmp(old_edid, cur_edid, sizeof(*cur_edid))) {
+ changed = true;
+ DRM_DEBUG_KMS("[CONNECTOR:%d:%s] edid updated\n",
+ connector->base.id,
+ connector->name);
+ }
+ }
+ }
+ drm_connector_list_iter_end(&conn_iter);
+ mutex_unlock(&dev->mode_config.mutex);
+
+ if (changed)
+ drm_kms_helper_hotplug_event(dev);
+
+ return changed;
+}
+
static void i915_hpd_poll_init_work(struct work_struct *work)
{
struct drm_i915_private *dev_priv =
@@ -552,7 +633,7 @@ static void i915_hpd_poll_init_work(struct work_struct *work)
* in the middle of disabling polling
*/
if (!enabled)
- drm_helper_hpd_irq_event(dev);
+ intel_hpd_irq_event(dev);
}
/**
--
2.18.0
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