1 files changed, 696 insertions, 158 deletions

diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
index a1bb157bfdfa..09b12c30df69 100644
--- a/drivers/gpu/drm/drm_probe_helper.c
+++ b/drivers/gpu/drm/drm_probe_helper.c
@@ -32,14 +32,16 @@
 #include <linux/export.h>
 #include <linux/moduleparam.h>
 
-#include <drm/drmP.h>
-#include <drm/drm_client.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_client_event.h>
 #include <drm/drm_crtc.h>
-#include <drm/drm_fourcc.h>
-#include <drm/drm_crtc_helper.h>
-#include <drm/drm_fb_helper.h>
 #include <drm/drm_edid.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_managed.h>
 #include <drm/drm_modeset_helper_vtables.h>
+#include <drm/drm_print.h>
+#include <drm/drm_probe_helper.h>
+#include <drm/drm_sysfs.h>
 
 #include "drm_crtc_helper_internal.h"
 
@@ -84,26 +86,28 @@ drm_mode_validate_flag(const struct drm_display_mode *mode,
 	return MODE_OK;
 }
 
-static enum drm_mode_status
+static int
 drm_mode_validate_pipeline(struct drm_display_mode *mode,
-			    struct drm_connector *connector)
+			   struct drm_connector *connector,
+			   struct drm_modeset_acquire_ctx *ctx,
+			   enum drm_mode_status *status)
 {
 	struct drm_device *dev = connector->dev;
-	enum drm_mode_status ret = MODE_OK;
 	struct drm_encoder *encoder;
-	int i;
+	int ret;
 
 	/* Step 1: Validate against connector */
-	ret = drm_connector_mode_valid(connector, mode);
-	if (ret != MODE_OK)
+	ret = drm_connector_mode_valid(connector, mode, ctx, status);
+	if (ret || *status != MODE_OK)
 		return ret;
 
 	/* Step 2: Validate against encoders and crtcs */
-	drm_connector_for_each_possible_encoder(connector, encoder, i) {
+	drm_connector_for_each_possible_encoder(connector, encoder) {
+		struct drm_bridge *bridge;
 		struct drm_crtc *crtc;
 
-		ret = drm_encoder_mode_valid(encoder, mode);
-		if (ret != MODE_OK) {
+		*status = drm_encoder_mode_valid(encoder, mode);
+		if (*status != MODE_OK) {
 			/* No point in continuing for crtc check as this encoder
 			 * will not accept the mode anyway. If all encoders
 			 * reject the mode then, at exit, ret will not be
@@ -111,8 +115,12 @@ drm_mode_validate_pipeline(struct drm_display_mode *mode,
 			continue;
 		}
 
-		ret = drm_bridge_mode_valid(encoder->bridge, mode);
-		if (ret != MODE_OK) {
+		bridge = drm_bridge_chain_get_first_bridge(encoder);
+		*status = drm_bridge_chain_mode_valid(bridge,
+						      &connector->display_info,
+						      mode);
+		drm_bridge_put(bridge);
+		if (*status != MODE_OK) {
 			/* There is also no point in continuing for crtc check
 			 * here. */
 			continue;
@@ -122,17 +130,17 @@ drm_mode_validate_pipeline(struct drm_display_mode *mode,
 			if (!drm_encoder_crtc_ok(encoder, crtc))
 				continue;
 
-			ret = drm_crtc_mode_valid(crtc, mode);
-			if (ret == MODE_OK) {
+			*status = drm_crtc_mode_valid(crtc, mode);
+			if (*status == MODE_OK) {
 				/* If we get to this point there is at least
 				 * one combination of encoder+crtc that works
 				 * for this mode. Lets return now. */
-				return ret;
+				return 0;
 			}
 		}
 	}
 
-	return ret;
+	return 0;
 }
 
 static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
@@ -156,6 +164,8 @@ static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
 				continue;
 		}
 
+		/* Mark the matching mode as being preferred by the user */
+		mode->type |= DRM_MODE_TYPE_USERDEF;
 		return 0;
 	}
 
@@ -191,53 +201,74 @@ enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder,
 	return encoder_funcs->mode_valid(encoder, mode);
 }
 
-enum drm_mode_status drm_connector_mode_valid(struct drm_connector *connector,
-					      struct drm_display_mode *mode)
+int
+drm_connector_mode_valid(struct drm_connector *connector,
+			 const struct drm_display_mode *mode,
+			 struct drm_modeset_acquire_ctx *ctx,
+			 enum drm_mode_status *status)
 {
 	const struct drm_connector_helper_funcs *connector_funcs =
 		connector->helper_private;
+	int ret = 0;
+
+	if (!connector_funcs)
+		*status = MODE_OK;
+	else if (connector_funcs->mode_valid_ctx)
+		ret = connector_funcs->mode_valid_ctx(connector, mode, ctx,
+						      status);
+	else if (connector_funcs->mode_valid)
+		*status = connector_funcs->mode_valid(connector, mode);
+	else
+		*status = MODE_OK;
 
-	if (!connector_funcs || !connector_funcs->mode_valid)
-		return MODE_OK;
+	return ret;
+}
 
-	return connector_funcs->mode_valid(connector, mode);
+static void drm_kms_helper_disable_hpd(struct drm_device *dev)
+{
+	struct drm_connector *connector;
+	struct drm_connector_list_iter conn_iter;
+
+	drm_connector_list_iter_begin(dev, &conn_iter);
+	drm_for_each_connector_iter(connector, &conn_iter) {
+		const struct drm_connector_helper_funcs *funcs =
+			connector->helper_private;
+
+		if (funcs && funcs->disable_hpd)
+			funcs->disable_hpd(connector);
+	}
+	drm_connector_list_iter_end(&conn_iter);
 }
 
-#define DRM_OUTPUT_POLL_PERIOD (10*HZ)
-/**
- * drm_kms_helper_poll_enable - re-enable output polling.
- * @dev: drm_device
- *
- * This function re-enables the output polling work, after it has been
- * temporarily disabled using drm_kms_helper_poll_disable(), for example over
- * suspend/resume.
- *
- * Drivers can call this helper from their device resume implementation. It is
- * not an error to call this even when output polling isn't enabled.
- *
- * Note that calls to enable and disable polling must be strictly ordered, which
- * is automatically the case when they're only call from suspend/resume
- * callbacks.
- */
-void drm_kms_helper_poll_enable(struct drm_device *dev)
+static bool drm_kms_helper_enable_hpd(struct drm_device *dev)
 {
 	bool poll = false;
 	struct drm_connector *connector;
 	struct drm_connector_list_iter conn_iter;
-	unsigned long delay = DRM_OUTPUT_POLL_PERIOD;
-
-	if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
-		return;
 
 	drm_connector_list_iter_begin(dev, &conn_iter);
 	drm_for_each_connector_iter(connector, &conn_iter) {
+		const struct drm_connector_helper_funcs *funcs =
+			connector->helper_private;
+
+		if (funcs && funcs->enable_hpd)
+			funcs->enable_hpd(connector);
+
 		if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
 					 DRM_CONNECTOR_POLL_DISCONNECT))
 			poll = true;
 	}
 	drm_connector_list_iter_end(&conn_iter);
 
-	if (dev->mode_config.delayed_event) {
+	return poll;
+}
+
+#define DRM_OUTPUT_POLL_PERIOD (10*HZ)
+static void reschedule_output_poll_work(struct drm_device *dev)
+{
+	unsigned long delay = DRM_OUTPUT_POLL_PERIOD;
+
+	if (dev->mode_config.delayed_event)
 		/*
 		 * FIXME:
 		 *
@@ -248,19 +279,83 @@ void drm_kms_helper_poll_enable(struct drm_device *dev)
 		 * drm_helper_probe_single_connector_modes() in case the poll
 		 * was enabled before.
 		 */
-		poll = true;
 		delay = HZ;
-	}
 
-	if (poll)
-		schedule_delayed_work(&dev->mode_config.output_poll_work, delay);
+	schedule_delayed_work(&dev->mode_config.output_poll_work, delay);
+}
+
+/**
+ * drm_kms_helper_poll_enable - re-enable output polling.
+ * @dev: drm_device
+ *
+ * This function re-enables the output polling work, after it has been
+ * temporarily disabled using drm_kms_helper_poll_disable(), for example over
+ * suspend/resume.
+ *
+ * Drivers can call this helper from their device resume implementation. It is
+ * not an error to call this even when output polling isn't enabled.
+ *
+ * If device polling was never initialized before, this call will trigger a
+ * warning and return.
+ *
+ * Note that calls to enable and disable polling must be strictly ordered, which
+ * is automatically the case when they're only call from suspend/resume
+ * callbacks.
+ */
+void drm_kms_helper_poll_enable(struct drm_device *dev)
+{
+	if (drm_WARN_ON_ONCE(dev, !dev->mode_config.poll_enabled) ||
+	    !drm_kms_helper_poll || dev->mode_config.poll_running)
+		return;
+
+	if (drm_kms_helper_enable_hpd(dev) ||
+	    dev->mode_config.delayed_event)
+		reschedule_output_poll_work(dev);
+
+	dev->mode_config.poll_running = true;
 }
 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
 
+/**
+ * drm_kms_helper_poll_reschedule - reschedule the output polling work
+ * @dev: drm_device
+ *
+ * This function reschedules the output polling work, after polling for a
+ * connector has been enabled.
+ *
+ * Drivers must call this helper after enabling polling for a connector by
+ * setting %DRM_CONNECTOR_POLL_CONNECT / %DRM_CONNECTOR_POLL_DISCONNECT flags
+ * in drm_connector::polled. Note that after disabling polling by clearing these
+ * flags for a connector will stop the output polling work automatically if
+ * the polling is disabled for all other connectors as well.
+ *
+ * The function can be called only after polling has been enabled by calling
+ * drm_kms_helper_poll_init() / drm_kms_helper_poll_enable().
+ */
+void drm_kms_helper_poll_reschedule(struct drm_device *dev)
+{
+	if (dev->mode_config.poll_running)
+		reschedule_output_poll_work(dev);
+}
+EXPORT_SYMBOL(drm_kms_helper_poll_reschedule);
+
+static int detect_connector_status(struct drm_connector *connector,
+				   struct drm_modeset_acquire_ctx *ctx,
+				   bool force)
+{
+	const struct drm_connector_helper_funcs *funcs = connector->helper_private;
+
+	if (funcs->detect_ctx)
+		return funcs->detect_ctx(connector, ctx, force);
+	else if (connector->funcs->detect)
+		return connector->funcs->detect(connector, force);
+
+	return connector_status_connected;
+}
+
 static enum drm_connector_status
 drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force)
 {
-	const struct drm_connector_helper_funcs *funcs = connector->helper_private;
 	struct drm_modeset_acquire_ctx ctx;
 	int ret;
 
@@ -268,14 +363,8 @@ drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force)
 
 retry:
 	ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx);
-	if (!ret) {
-		if (funcs->detect_ctx)
-			ret = funcs->detect_ctx(connector, &ctx, force);
-		else if (connector->funcs->detect)
-			ret = connector->funcs->detect(connector, force);
-		else
-			ret = connector_status_connected;
-	}
+	if (!ret)
+		ret = detect_connector_status(connector, &ctx, force);
 
 	if (ret == -EDEADLK) {
 		drm_modeset_backoff(&ctx);
@@ -285,6 +374,9 @@ retry:
 	if (WARN_ON(ret < 0))
 		ret = connector_status_unknown;
 
+	if (ret != connector->status)
+		connector->epoch_counter += 1;
+
 	drm_modeset_drop_locks(&ctx);
 	drm_modeset_acquire_fini(&ctx);
 
@@ -306,7 +398,6 @@ drm_helper_probe_detect(struct drm_connector *connector,
 			struct drm_modeset_acquire_ctx *ctx,
 			bool force)
 {
-	const struct drm_connector_helper_funcs *funcs = connector->helper_private;
 	struct drm_device *dev = connector->dev;
 	int ret;
 
@@ -317,15 +408,95 @@ drm_helper_probe_detect(struct drm_connector *connector,
 	if (ret)
 		return ret;
 
-	if (funcs->detect_ctx)
-		return funcs->detect_ctx(connector, ctx, force);
-	else if (connector->funcs->detect)
-		return connector->funcs->detect(connector, force);
-	else
-		return connector_status_connected;
+	ret = detect_connector_status(connector, ctx, force);
+
+	if (ret != connector->status)
+		connector->epoch_counter += 1;
+
+	return ret;
 }
 EXPORT_SYMBOL(drm_helper_probe_detect);
 
+static int drm_helper_probe_get_modes(struct drm_connector *connector)
+{
+	const struct drm_connector_helper_funcs *connector_funcs =
+		connector->helper_private;
+	int count;
+
+	count = connector_funcs->get_modes(connector);
+
+	/* The .get_modes() callback should not return negative values. */
+	if (count < 0) {
+		drm_err(connector->dev, ".get_modes() returned %pe\n",
+			ERR_PTR(count));
+		count = 0;
+	}
+
+	/*
+	 * Fallback for when DDC probe failed in drm_get_edid() and thus skipped
+	 * override/firmware EDID.
+	 */
+	if (count == 0 && connector->status == connector_status_connected)
+		count = drm_edid_override_connector_update(connector);
+
+	return count;
+}
+
+static int __drm_helper_update_and_validate(struct drm_connector *connector,
+					    uint32_t maxX, uint32_t maxY,
+					    struct drm_modeset_acquire_ctx *ctx)
+{
+	struct drm_device *dev = connector->dev;
+	struct drm_display_mode *mode;
+	int mode_flags = 0;
+	int ret;
+
+	drm_connector_list_update(connector);
+
+	if (connector->interlace_allowed)
+		mode_flags |= DRM_MODE_FLAG_INTERLACE;
+	if (connector->doublescan_allowed)
+		mode_flags |= DRM_MODE_FLAG_DBLSCAN;
+	if (connector->stereo_allowed)
+		mode_flags |= DRM_MODE_FLAG_3D_MASK;
+
+	list_for_each_entry(mode, &connector->modes, head) {
+		if (mode->status != MODE_OK)
+			continue;
+
+		mode->status = drm_mode_validate_driver(dev, mode);
+		if (mode->status != MODE_OK)
+			continue;
+
+		mode->status = drm_mode_validate_size(mode, maxX, maxY);
+		if (mode->status != MODE_OK)
+			continue;
+
+		mode->status = drm_mode_validate_flag(mode, mode_flags);
+		if (mode->status != MODE_OK)
+			continue;
+
+		mode->status = drm_mode_validate_ycbcr420(mode, connector);
+		if (mode->status != MODE_OK)
+			continue;
+
+		ret = drm_mode_validate_pipeline(mode, connector, ctx,
+						 &mode->status);
+		if (ret) {
+			drm_dbg_kms(dev,
+				    "drm_mode_validate_pipeline failed: %d\n",
+				    ret);
+
+			if (drm_WARN_ON_ONCE(dev, ret != -EDEADLK))
+				mode->status = MODE_ERROR;
+			else
+				return -EDEADLK;
+		}
+	}
+
+	return 0;
+}
+
 /**
  * drm_helper_probe_single_connector_modes - get complete set of display modes
  * @connector: connector to probe
@@ -370,8 +541,9 @@ EXPORT_SYMBOL(drm_helper_probe_detect);
  *      (if specified)
  *    - drm_mode_validate_flag() checks the modes against basic connector
  *      capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
- *    - the optional &drm_connector_helper_funcs.mode_valid helper can perform
- *      driver and/or sink specific checks
+ *    - the optional &drm_connector_helper_funcs.mode_valid or
+ *      &drm_connector_helper_funcs.mode_valid_ctx helpers can perform driver
+ *      and/or sink specific checks
  *    - the optional &drm_crtc_helper_funcs.mode_valid,
  *      &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid
  *      helpers can perform driver and/or source specific checks which are also
@@ -389,11 +561,7 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
 {
 	struct drm_device *dev = connector->dev;
 	struct drm_display_mode *mode;
-	const struct drm_connector_helper_funcs *connector_funcs =
-		connector->helper_private;
 	int count = 0, ret;
-	int mode_flags = 0;
-	bool verbose_prune = true;
 	enum drm_connector_status old_status;
 	struct drm_modeset_acquire_ctx ctx;
 
@@ -401,8 +569,8 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
 
 	drm_modeset_acquire_init(&ctx, 0);
 
-	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
-			connector->name);
+	drm_dbg_kms(dev, "[CONNECTOR:%d:%s]\n", connector->base.id,
+		    connector->name);
 
 retry:
 	ret = drm_modeset_lock(&dev->mode_config.connection_mutex, &ctx);
@@ -445,11 +613,10 @@ retry:
 	 * check here, and if anything changed start the hotplug code.
 	 */
 	if (old_status != connector->status) {
-		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(connector->status));
+		drm_dbg_kms(dev, "[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(connector->status));
 
 		/*
 		 * The hotplug event code might call into the fb
@@ -459,79 +626,85 @@ retry:
 		 */
 		dev->mode_config.delayed_event = true;
 		if (dev->mode_config.poll_enabled)
-			schedule_delayed_work(&dev->mode_config.output_poll_work,
-					      0);
+			mod_delayed_work(system_wq,
+					 &dev->mode_config.output_poll_work,
+					 0);
 	}
 
-	/* Re-enable polling in case the global poll config changed. */
-	if (drm_kms_helper_poll != dev->mode_config.poll_running)
+	/*
+	 * Re-enable polling in case the global poll config changed but polling
+	 * is still initialized.
+	 */
+	if (dev->mode_config.poll_enabled)
 		drm_kms_helper_poll_enable(dev);
 
-	dev->mode_config.poll_running = drm_kms_helper_poll;
-
 	if (connector->status == connector_status_disconnected) {
-		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
-			connector->base.id, connector->name);
+		drm_dbg_kms(dev, "[CONNECTOR:%d:%s] disconnected\n",
+			    connector->base.id, connector->name);
 		drm_connector_update_edid_property(connector, NULL);
-		verbose_prune = false;
-		goto prune;
+		drm_mode_prune_invalid(dev, &connector->modes, false);
+		goto exit;
 	}
 
-	count = (*connector_funcs->get_modes)(connector);
+	count = drm_helper_probe_get_modes(connector);
 
-	if (count == 0 && connector->status == connector_status_connected)
+	if (count == 0 && (connector->status == connector_status_connected ||
+			   connector->status == connector_status_unknown)) {
 		count = drm_add_modes_noedid(connector, 1024, 768);
-	count += drm_helper_probe_add_cmdline_mode(connector);
-	if (count == 0)
-		goto prune;
 
-	drm_connector_list_update(connector);
-
-	if (connector->interlace_allowed)
-		mode_flags |= DRM_MODE_FLAG_INTERLACE;
-	if (connector->doublescan_allowed)
-		mode_flags |= DRM_MODE_FLAG_DBLSCAN;
-	if (connector->stereo_allowed)
-		mode_flags |= DRM_MODE_FLAG_3D_MASK;
-
-	list_for_each_entry(mode, &connector->modes, head) {
-		if (mode->status == MODE_OK)
-			mode->status = drm_mode_validate_driver(dev, mode);
-
-		if (mode->status == MODE_OK)
-			mode->status = drm_mode_validate_size(mode, maxX, maxY);
-
-		if (mode->status == MODE_OK)
-			mode->status = drm_mode_validate_flag(mode, mode_flags);
+		/*
+		 * Section 4.2.2.6 (EDID Corruption Detection) of the DP 1.4a
+		 * Link CTS specifies that 640x480 (the official "failsafe"
+		 * mode) needs to be the default if there's no EDID.
+		 */
+		if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort)
+			drm_set_preferred_mode(connector, 640, 480);
+	}
+	count += drm_helper_probe_add_cmdline_mode(connector);
+	if (count != 0) {
+		ret = __drm_helper_update_and_validate(connector, maxX, maxY, &ctx);
+		if (ret == -EDEADLK) {
+			drm_modeset_backoff(&ctx);
+			goto retry;
+		}
+	}
 
-		if (mode->status == MODE_OK)
-			mode->status = drm_mode_validate_pipeline(mode,
-								  connector);
+	drm_mode_prune_invalid(dev, &connector->modes, true);
 
-		if (mode->status == MODE_OK)
-			mode->status = drm_mode_validate_ycbcr420(mode,
-								  connector);
+	/*
+	 * Displayport spec section 5.2.1.2 ("Video Timing Format") says that
+	 * all detachable sinks shall support 640x480 @60Hz as a fail safe
+	 * mode. If all modes were pruned, perhaps because they need more
+	 * lanes or a higher pixel clock than available, at least try to add
+	 * in 640x480.
+	 */
+	if (list_empty(&connector->modes) &&
+	    connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort) {
+		count = drm_add_modes_noedid(connector, 640, 480);
+		ret = __drm_helper_update_and_validate(connector, maxX, maxY, &ctx);
+		if (ret == -EDEADLK) {
+			drm_modeset_backoff(&ctx);
+			goto retry;
+		}
+		drm_mode_prune_invalid(dev, &connector->modes, true);
 	}
 
-prune:
-	drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
-
+exit:
 	drm_modeset_drop_locks(&ctx);
 	drm_modeset_acquire_fini(&ctx);
 
 	if (list_empty(&connector->modes))
 		return 0;
 
-	list_for_each_entry(mode, &connector->modes, head)
-		mode->vrefresh = drm_mode_vrefresh(mode);
-
 	drm_mode_sort(&connector->modes);
 
-	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
-			connector->name);
+	drm_dbg_kms(dev, "[CONNECTOR:%d:%s] probed modes:\n",
+		    connector->base.id, connector->name);
+
 	list_for_each_entry(mode, &connector->modes, head) {
 		drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
-		drm_mode_debug_printmodeline(mode);
+		drm_dbg_kms(dev, "Probed mode: " DRM_MODE_FMT "\n",
+			    DRM_MODE_ARG(mode));
 	}
 
 	return count;
@@ -543,7 +716,7 @@ EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
  * @dev: drm_device whose connector state changed
  *
  * This function fires off the uevent for userspace and also calls the
- * output_poll_changed function, which is most commonly used to inform the fbdev
+ * client hotplug function, which is most commonly used to inform the fbdev
  * emulation code and allow it to update the fbcon output configuration.
  *
  * Drivers should call this from their hotplug handling code when a change is
@@ -553,18 +726,33 @@ EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
  *
  * This function must be called from process context with no mode
  * setting locks held.
+ *
+ * If only a single connector has changed, consider calling
+ * drm_kms_helper_connector_hotplug_event() instead.
  */
 void drm_kms_helper_hotplug_event(struct drm_device *dev)
 {
-	/* send a uevent + call fbdev */
 	drm_sysfs_hotplug_event(dev);
-	if (dev->mode_config.funcs->output_poll_changed)
-		dev->mode_config.funcs->output_poll_changed(dev);
-
 	drm_client_dev_hotplug(dev);
 }
 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
 
+/**
+ * drm_kms_helper_connector_hotplug_event - fire off a KMS connector hotplug event
+ * @connector: drm_connector which has changed
+ *
+ * This is the same as drm_kms_helper_hotplug_event(), except it fires a more
+ * fine-grained uevent for a single connector.
+ */
+void drm_kms_helper_connector_hotplug_event(struct drm_connector *connector)
+{
+	struct drm_device *dev = connector->dev;
+
+	drm_sysfs_connector_hotplug_event(connector);
+	drm_client_dev_hotplug(dev);
+}
+EXPORT_SYMBOL(drm_kms_helper_connector_hotplug_event);
+
 static void output_poll_execute(struct work_struct *work)
 {
 	struct delayed_work *delayed_work = to_delayed_work(work);
@@ -573,13 +761,22 @@ static void output_poll_execute(struct work_struct *work)
 	struct drm_connector_list_iter conn_iter;
 	enum drm_connector_status old_status;
 	bool repoll = false, changed;
+	u64 old_epoch_counter;
+
+	if (!dev->mode_config.poll_enabled)
+		return;
 
 	/* Pick up any changes detected by the probe functions. */
 	changed = dev->mode_config.delayed_event;
 	dev->mode_config.delayed_event = false;
 
-	if (!drm_kms_helper_poll)
+	if (!drm_kms_helper_poll) {
+		if (dev->mode_config.poll_running) {
+			drm_kms_helper_disable_hpd(dev);
+			dev->mode_config.poll_running = false;
+		}
 		goto out;
+	}
 
 	if (!mutex_trylock(&dev->mode_config.mutex)) {
 		repoll = true;
@@ -606,8 +803,9 @@ static void output_poll_execute(struct work_struct *work)
 
 		repoll = true;
 
+		old_epoch_counter = connector->epoch_counter;
 		connector->status = drm_helper_probe_detect(connector, NULL, false);
-		if (old_status != connector->status) {
+		if (old_epoch_counter != connector->epoch_counter) {
 			const char *old, *new;
 
 			/*
@@ -631,11 +829,12 @@ static void output_poll_execute(struct work_struct *work)
 			old = drm_get_connector_status_name(old_status);
 			new = drm_get_connector_status_name(connector->status);
 
-			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
-				      "status updated from %s to %s\n",
-				      connector->base.id,
-				      connector->name,
-				      old, new);
+			drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s\n",
+				    connector->base.id, connector->name,
+				    old, new);
+			drm_dbg_kms(dev, "[CONNECTOR:%d:%s] epoch counter %llu -> %llu\n",
+				    connector->base.id, connector->name,
+				    old_epoch_counter, connector->epoch_counter);
 
 			changed = true;
 		}
@@ -682,15 +881,24 @@ EXPORT_SYMBOL(drm_kms_helper_is_poll_worker);
  * not an error to call this even when output polling isn't enabled or already
  * disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable().
  *
+ * If however, the polling was never initialized, this call will trigger a
+ * warning and return.
+ *
  * Note that calls to enable and disable polling must be strictly ordered, which
  * is automatically the case when they're only call from suspend/resume
  * callbacks.
  */
 void drm_kms_helper_poll_disable(struct drm_device *dev)
 {
-	if (!dev->mode_config.poll_enabled)
+	if (drm_WARN_ON(dev, !dev->mode_config.poll_enabled))
 		return;
+
+	if (dev->mode_config.poll_running)
+		drm_kms_helper_disable_hpd(dev);
+
 	cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
+
+	dev->mode_config.poll_running = false;
 }
 EXPORT_SYMBOL(drm_kms_helper_poll_disable);
 
@@ -698,7 +906,7 @@ EXPORT_SYMBOL(drm_kms_helper_poll_disable);
  * drm_kms_helper_poll_init - initialize and enable output polling
  * @dev: drm_device
  *
- * This function intializes and then also enables output polling support for
+ * This function initializes and then also enables output polling support for
  * @dev. Drivers which do not have reliable hotplug support in hardware can use
  * this helper infrastructure to regularly poll such connectors for changes in
  * their connection state.
@@ -728,10 +936,122 @@ EXPORT_SYMBOL(drm_kms_helper_poll_init);
  */
 void drm_kms_helper_poll_fini(struct drm_device *dev)
 {
+	if (!dev->mode_config.poll_enabled)
+		return;
+
 	drm_kms_helper_poll_disable(dev);
+
+	dev->mode_config.poll_enabled = false;
 }
 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
 
+static void drm_kms_helper_poll_init_release(struct drm_device *dev, void *res)
+{
+	drm_kms_helper_poll_fini(dev);
+}
+
+/**
+ * drmm_kms_helper_poll_init - initialize and enable output polling
+ * @dev: drm_device
+ *
+ * This function initializes and then also enables output polling support for
+ * @dev similar to drm_kms_helper_poll_init(). Polling will automatically be
+ * cleaned up when the DRM device goes away.
+ *
+ * See drm_kms_helper_poll_init() for more information.
+ */
+void drmm_kms_helper_poll_init(struct drm_device *dev)
+{
+	int ret;
+
+	drm_kms_helper_poll_init(dev);
+
+	ret = drmm_add_action_or_reset(dev, drm_kms_helper_poll_init_release, dev);
+	if (ret)
+		drm_warn(dev, "Connector status will not be updated, error %d\n", ret);
+}
+EXPORT_SYMBOL(drmm_kms_helper_poll_init);
+
+static bool check_connector_changed(struct drm_connector *connector)
+{
+	struct drm_device *dev = connector->dev;
+	enum drm_connector_status old_status;
+	u64 old_epoch_counter;
+
+	/* Only handle HPD capable connectors. */
+	drm_WARN_ON(dev, !(connector->polled & DRM_CONNECTOR_POLL_HPD));
+
+	drm_WARN_ON(dev, !mutex_is_locked(&dev->mode_config.mutex));
+
+	old_status = connector->status;
+	old_epoch_counter = connector->epoch_counter;
+	connector->status = drm_helper_probe_detect(connector, NULL, false);
+
+	if (old_epoch_counter == connector->epoch_counter) {
+		drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Same epoch counter %llu\n",
+			    connector->base.id,
+			    connector->name,
+			    connector->epoch_counter);
+
+		return false;
+	}
+
+	drm_dbg_kms(dev, "[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(connector->status));
+
+	drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Changed epoch counter %llu => %llu\n",
+		    connector->base.id,
+		    connector->name,
+		    old_epoch_counter,
+		    connector->epoch_counter);
+
+	return true;
+}
+
+/**
+ * drm_connector_helper_hpd_irq_event - hotplug processing
+ * @connector: drm_connector
+ *
+ * Drivers can use this helper function to run a detect cycle on a connector
+ * which has the DRM_CONNECTOR_POLL_HPD flag set in its &polled member.
+ *
+ * This helper function is useful for drivers which can track hotplug
+ * interrupts for a single connector. Drivers that want to send a
+ * hotplug event for all connectors or can't track hotplug interrupts
+ * per connector need to use drm_helper_hpd_irq_event().
+ *
+ * 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.
+ *
+ * Returns:
+ * A boolean indicating whether the connector status changed or not
+ */
+bool drm_connector_helper_hpd_irq_event(struct drm_connector *connector)
+{
+	struct drm_device *dev = connector->dev;
+	bool changed;
+
+	mutex_lock(&dev->mode_config.mutex);
+	changed = check_connector_changed(connector);
+	mutex_unlock(&dev->mode_config.mutex);
+
+	if (changed) {
+		drm_kms_helper_connector_hotplug_event(connector);
+		drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Sent hotplug event\n",
+			    connector->base.id,
+			    connector->name);
+	}
+
+	return changed;
+}
+EXPORT_SYMBOL(drm_connector_helper_hpd_irq_event);
+
 /**
  * drm_helper_hpd_irq_event - hotplug processing
  * @dev: drm_device
@@ -745,22 +1065,25 @@ EXPORT_SYMBOL(drm_kms_helper_poll_fini);
  * interrupts for each connector.
  *
  * Drivers which support hotplug interrupts for each connector individually and
- * which have a more fine-grained detect logic should bypass this code and
- * directly call drm_kms_helper_hotplug_event() in case the connector state
- * changed.
+ * which have a more fine-grained detect logic can use
+ * drm_connector_helper_hpd_irq_event(). Alternatively, they should bypass this
+ * code and directly call drm_kms_helper_hotplug_event() in case the connector
+ * state changed.
  *
  * 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.
+ *
+ * Returns:
+ * A boolean indicating whether the connector status changed or not
  */
 bool drm_helper_hpd_irq_event(struct drm_device *dev)
 {
-	struct drm_connector *connector;
+	struct drm_connector *connector, *first_changed_connector = NULL;
 	struct drm_connector_list_iter conn_iter;
-	enum drm_connector_status old_status;
-	bool changed = false;
+	int changed = 0;
 
 	if (!dev->mode_config.poll_enabled)
 		return false;
@@ -772,23 +1095,238 @@ bool drm_helper_hpd_irq_event(struct drm_device *dev)
 		if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
 			continue;
 
-		old_status = connector->status;
+		if (check_connector_changed(connector)) {
+			if (!first_changed_connector) {
+				drm_connector_get(connector);
+				first_changed_connector = connector;
+			}
 
-		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,
-			      connector->name,
-			      drm_get_connector_status_name(old_status),
-			      drm_get_connector_status_name(connector->status));
-		if (old_status != connector->status)
-			changed = true;
+			changed++;
+		}
 	}
 	drm_connector_list_iter_end(&conn_iter);
 	mutex_unlock(&dev->mode_config.mutex);
 
-	if (changed)
+	if (changed == 1)
+		drm_kms_helper_connector_hotplug_event(first_changed_connector);
+	else if (changed > 0)
 		drm_kms_helper_hotplug_event(dev);
 
+	if (first_changed_connector)
+		drm_connector_put(first_changed_connector);
+
 	return changed;
 }
 EXPORT_SYMBOL(drm_helper_hpd_irq_event);
+
+/**
+ * drm_crtc_helper_mode_valid_fixed - Validates a display mode
+ * @crtc: the crtc
+ * @mode: the mode to validate
+ * @fixed_mode: the display hardware's mode
+ *
+ * Returns:
+ * MODE_OK on success, or another mode-status code otherwise.
+ */
+enum drm_mode_status drm_crtc_helper_mode_valid_fixed(struct drm_crtc *crtc,
+						      const struct drm_display_mode *mode,
+						      const struct drm_display_mode *fixed_mode)
+{
+	if (mode->hdisplay != fixed_mode->hdisplay && mode->vdisplay != fixed_mode->vdisplay)
+		return MODE_ONE_SIZE;
+	else if (mode->hdisplay != fixed_mode->hdisplay)
+		return MODE_ONE_WIDTH;
+	else if (mode->vdisplay != fixed_mode->vdisplay)
+		return MODE_ONE_HEIGHT;
+
+	return MODE_OK;
+}
+EXPORT_SYMBOL(drm_crtc_helper_mode_valid_fixed);
+
+/**
+ * drm_connector_helper_get_modes_fixed - Duplicates a display mode for a connector
+ * @connector: the connector
+ * @fixed_mode: the display hardware's mode
+ *
+ * This function duplicates a display modes for a connector. Drivers for hardware
+ * that only supports a single fixed mode can use this function in their connector's
+ * get_modes helper.
+ *
+ * Returns:
+ * The number of created modes.
+ */
+int drm_connector_helper_get_modes_fixed(struct drm_connector *connector,
+					 const struct drm_display_mode *fixed_mode)
+{
+	struct drm_device *dev = connector->dev;
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(dev, fixed_mode);
+	if (!mode) {
+		drm_err(dev, "Failed to duplicate mode " DRM_MODE_FMT "\n",
+			DRM_MODE_ARG(fixed_mode));
+		return 0;
+	}
+
+	if (mode->name[0] == '\0')
+		drm_mode_set_name(mode);
+
+	mode->type |= DRM_MODE_TYPE_PREFERRED;
+	drm_mode_probed_add(connector, mode);
+
+	if (mode->width_mm)
+		connector->display_info.width_mm = mode->width_mm;
+	if (mode->height_mm)
+		connector->display_info.height_mm = mode->height_mm;
+
+	return 1;
+}
+EXPORT_SYMBOL(drm_connector_helper_get_modes_fixed);
+
+/**
+ * drm_connector_helper_get_modes - Read EDID and update connector.
+ * @connector: The connector
+ *
+ * Read the EDID using drm_edid_read() (which requires that connector->ddc is
+ * set), and update the connector using the EDID.
+ *
+ * This can be used as the "default" connector helper .get_modes() hook if the
+ * driver does not need any special processing. This is sets the example what
+ * custom .get_modes() hooks should do regarding EDID read and connector update.
+ *
+ * Returns: Number of modes.
+ */
+int drm_connector_helper_get_modes(struct drm_connector *connector)
+{
+	const struct drm_edid *drm_edid;
+	int count;
+
+	drm_edid = drm_edid_read(connector);
+
+	/*
+	 * Unconditionally update the connector. If the EDID was read
+	 * successfully, fill in the connector information derived from the
+	 * EDID. Otherwise, if the EDID is NULL, clear the connector
+	 * information.
+	 */
+	drm_edid_connector_update(connector, drm_edid);
+
+	count = drm_edid_connector_add_modes(connector);
+
+	drm_edid_free(drm_edid);
+
+	return count;
+}
+EXPORT_SYMBOL(drm_connector_helper_get_modes);
+
+/**
+ * drm_connector_helper_tv_get_modes - Fills the modes availables to a TV connector
+ * @connector: The connector
+ *
+ * Fills the available modes for a TV connector based on the supported
+ * TV modes, and the default mode expressed by the kernel command line.
+ *
+ * This can be used as the default TV connector helper .get_modes() hook
+ * if the driver does not need any special processing.
+ *
+ * Returns:
+ * The number of modes added to the connector.
+ */
+int drm_connector_helper_tv_get_modes(struct drm_connector *connector)
+{
+	struct drm_device *dev = connector->dev;
+	struct drm_property *tv_mode_property =
+		dev->mode_config.tv_mode_property;
+	struct drm_cmdline_mode *cmdline = &connector->cmdline_mode;
+	unsigned int ntsc_modes = BIT(DRM_MODE_TV_MODE_NTSC) |
+		BIT(DRM_MODE_TV_MODE_NTSC_443) |
+		BIT(DRM_MODE_TV_MODE_NTSC_J) |
+		BIT(DRM_MODE_TV_MODE_PAL_M);
+	unsigned int pal_modes = BIT(DRM_MODE_TV_MODE_PAL) |
+		BIT(DRM_MODE_TV_MODE_PAL_N) |
+		BIT(DRM_MODE_TV_MODE_SECAM);
+	unsigned int tv_modes[2] = { UINT_MAX, UINT_MAX };
+	unsigned int i, supported_tv_modes = 0;
+
+	if (!tv_mode_property)
+		return 0;
+
+	for (i = 0; i < tv_mode_property->num_values; i++)
+		supported_tv_modes |= BIT(tv_mode_property->values[i]);
+
+	if (((supported_tv_modes & ntsc_modes) &&
+	     (supported_tv_modes & pal_modes)) ||
+	    (supported_tv_modes & BIT(DRM_MODE_TV_MODE_MONOCHROME))) {
+		uint64_t default_mode;
+
+		if (drm_object_property_get_default_value(&connector->base,
+							  tv_mode_property,
+							  &default_mode))
+			return 0;
+
+		if (cmdline->tv_mode_specified)
+			default_mode = cmdline->tv_mode;
+
+		if (BIT(default_mode) & ntsc_modes) {
+			tv_modes[0] = DRM_MODE_TV_MODE_NTSC;
+			tv_modes[1] = DRM_MODE_TV_MODE_PAL;
+		} else {
+			tv_modes[0] = DRM_MODE_TV_MODE_PAL;
+			tv_modes[1] = DRM_MODE_TV_MODE_NTSC;
+		}
+	} else if (supported_tv_modes & ntsc_modes) {
+		tv_modes[0] = DRM_MODE_TV_MODE_NTSC;
+	} else if (supported_tv_modes & pal_modes) {
+		tv_modes[0] = DRM_MODE_TV_MODE_PAL;
+	} else {
+		return 0;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(tv_modes); i++) {
+		struct drm_display_mode *mode;
+
+		if (tv_modes[i] == DRM_MODE_TV_MODE_NTSC)
+			mode = drm_mode_analog_ntsc_480i(dev);
+		else if (tv_modes[i] == DRM_MODE_TV_MODE_PAL)
+			mode = drm_mode_analog_pal_576i(dev);
+		else
+			break;
+		if (!mode)
+			return i;
+		if (!i)
+			mode->type |= DRM_MODE_TYPE_PREFERRED;
+		drm_mode_probed_add(connector, mode);
+	}
+
+	return i;
+}
+EXPORT_SYMBOL(drm_connector_helper_tv_get_modes);
+
+/**
+ * drm_connector_helper_detect_from_ddc - Read EDID and detect connector status.
+ * @connector: The connector
+ * @ctx: Acquire context
+ * @force: Perform screen-destructive operations, if necessary
+ *
+ * Detects the connector status by reading the EDID using drm_probe_ddc(),
+ * which requires connector->ddc to be set. Returns connector_status_connected
+ * on success or connector_status_disconnected on failure.
+ *
+ * Returns:
+ * The connector status as defined by enum drm_connector_status.
+ */
+int drm_connector_helper_detect_from_ddc(struct drm_connector *connector,
+					 struct drm_modeset_acquire_ctx *ctx,
+					 bool force)
+{
+	struct i2c_adapter *ddc = connector->ddc;
+
+	if (!ddc)
+		return connector_status_unknown;
+
+	if (drm_probe_ddc(ddc))
+		return connector_status_connected;
+
+	return connector_status_disconnected;
+}
+EXPORT_SYMBOL(drm_connector_helper_detect_from_ddc);