Commit d482e5fa authored by Dave Airlie's avatar Dave Airlie
Browse files

Revert "drm: kms_helper: don't lose hotplug event" 



This reverts commit 160954b7.

This was rearming the workqueue with a 0 timeout, causing
a WARN_ON, and possible loop.

Daniel writes:
"I've looked a bit into this and I think we need to have a separate
work struct for recovering these lost hotplug events since the
continuous self-rearming case is a real risk (e.g. if a connector
flip-flops all the time). At least I don't see a sane way to block out
re-arming with the current code in a simple way. So reverting the
offender seems like the right thing and I'll go back to the drawing
board for 3.12."

Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
parent 421cda3e

drivers/gpu/drm/drm_crtc_helper.c

+1 −31
Original line number Diff line number Diff line
@@ -122,7 +122,6 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector, 
	int count = 0;

	int mode_flags = 0;

	bool verbose_prune = true;

	enum drm_connector_status old_status;



	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,

			drm_get_connector_name(connector));
@@ -138,32 +137,7 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector, 
		if (connector->funcs->force)

			connector->funcs->force(connector);

	} else {

		old_status = connector->status;



		connector->status = connector->funcs->detect(connector, true);



		/*

		 * Normally either the driver's hpd code or the poll loop should

		 * pick up any changes and fire the hotplug event. But if

		 * userspace sneaks in a probe, we might miss a change. Hence

		 * check here, and if anything changed start the hotplug code.

		 */

		if (old_status != connector->status) {

			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);



			/*

			 * The hotplug event code might call into the fb

			 * helpers, and so expects that we do not hold any

			 * locks. Fire up the poll struct instead, it will

			 * disable itself again.

			 */

			dev->mode_config.delayed_event = true;

			schedule_delayed_work(&dev->mode_config.output_poll_work,

					      0);

		}

	}



	/* Re-enable polling in case the global poll config changed. */
@@ -1011,11 +985,7 @@ static void output_poll_execute(struct work_struct *work) 
	struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);

	struct drm_connector *connector;

	enum drm_connector_status old_status;

	bool repoll = false, changed;



	/* Pick up any changes detected by the probe functions. */

	changed = dev->mode_config.delayed_event;

	dev->mode_config.delayed_event = false;

	bool repoll = false, changed = false;



	if (!drm_kms_helper_poll)

		return;

include/drm/drm_crtc.h

+0 −1
Original line number Diff line number Diff line
@@ -811,7 +811,6 @@ struct drm_mode_config { 
	/* output poll support */

	bool poll_enabled;

	bool poll_running;

	bool delayed_event;

	struct delayed_work output_poll_work;



	/* pointers to standard properties */

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