[PATCH] drm: handle HPD and polled connectors separately

[Daniel Vetter]

Instead of reusing the polling code for hpd handling, split them up.
This has a few consequences:
- Don't touch HPD capable connectors in the poll loop.
- Only touch HPD capable connectors in drm_helper_hpd_irq_event.
- Run the HPD handling directly instead of going through a work item -
  all callers already call drm_helper_hpd_irq_event from process
  context without holding the mode_config mutex.

The ultimate goal is that drivers grow some smarts about which
connectors have received a hotplug event and only call the detect code
of that connector. But that's a second step.

v2: s/hdp/hpd/, noticed by Adam Jackson. I can't type.

Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/drm_crtc_helper.c |   39 ++++++++++++++++++++++++++++--------
 1 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index 909a85c..5461ee6 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -942,9 +942,9 @@ static void output_poll_execute(struct work_struct *work)
 	mutex_lock(&dev->mode_config.mutex);
 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 
-		/* if this is HPD or polled don't check it -
-		   TV out for instance */
-		if (!connector->polled)
+		/* Ignore HPD capable connectors and connectors where we don't
+		 * want any hotplug detection at all for polling. */
+		if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
 			continue;
 
 		else if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DISCONNECT))
@@ -954,8 +954,7 @@ static void output_poll_execute(struct work_struct *work)
 		/* if we are connected and don't want to poll for disconnect
 		   skip it */
 		if (old_status == connector_status_connected &&
-		    !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT) &&
-		    !(connector->polled & DRM_CONNECTOR_POLL_HPD))
+		    !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
 			continue;
 
 		connector->status = connector->funcs->detect(connector, false);
@@ -1019,12 +1018,34 @@ EXPORT_SYMBOL(drm_kms_helper_poll_fini);
 
 void drm_helper_hpd_irq_event(struct drm_device *dev)
 {
+	struct drm_connector *connector;
+	enum drm_connector_status old_status;
+	bool changed = false;
+
 	if (!dev->mode_config.poll_enabled)
 		return;
 
-	/* kill timer and schedule immediate execution, this doesn't block */
-	cancel_delayed_work(&dev->mode_config.output_poll_work);
-	if (drm_kms_helper_poll)
-		queue_delayed_work(system_nrt_wq, &dev->mode_config.output_poll_work, 0);
+	mutex_lock(&dev->mode_config.mutex);
+	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+
+		/* Only handle HPD capable connectors. */
+		if (connector->polled != DRM_CONNECTOR_POLL_HPD)
+			continue;
+
+		old_status = connector->status;
+
+		connector->status = connector->funcs->detect(connector, false);
+		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %d to %d\n",
+			      connector->base.id,
+			      drm_get_connector_name(connector),
+			      old_status, connector->status);
+		if (old_status != connector->status)
+			changed = true;
+	}
+
+	mutex_unlock(&dev->mode_config.mutex);
+
+	if (changed)
+		drm_kms_helper_hotplug_event(dev);
 }
 EXPORT_SYMBOL(drm_helper_hpd_irq_event);
-- 
1.7.7.6