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Commit 42e5e657 authored by Daniel Vetter's avatar Daniel Vetter
Browse files

drm/i915: sync dp link status checks against atomic commmits 

Two bits:
- check actual atomic state, the legacy stuff can only be looked at
  from within the atomic_commit_tail function, since it's only
  protected by ordering and not by any locks.

- Make sure we don't wreak the work an ongoing nonblocking commit is
  doing.

v2: We need the crtc lock too, because a plane update might change it
without having to acquire the connection_mutex (Maarten). Use
Maarten's changes for this locking, while keeping the logic that uses
the connection->commit->hw_done signal for syncing with nonblocking
commits.

v3: The initial state objects from the hw state readout do not have a
commit object. Check for that (spotted by CI).

v4: Fix deadlock from jumping to put_power with locks still held.
    (mlankhorst)

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=103336
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99272


Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20171113160140.22679-1-maarten.lankhorst@linux.intel.com
parent fbba5559

drivers/gpu/drm/i915/intel_dp.c

+55 −6
Original line number Diff line number Diff line
@@ -4277,6 +4277,8 @@ intel_dp_check_link_status(struct intel_dp *intel_dp) 
{

	struct drm_i915_private *dev_priv = to_i915(intel_dp_to_dev(intel_dp));

	struct intel_encoder *intel_encoder = &dp_to_dig_port(intel_dp)->base;

	struct drm_connector_state *conn_state =

		intel_dp->attached_connector->base.state;

	u8 link_status[DP_LINK_STATUS_SIZE];



	WARN_ON(!drm_modeset_is_locked(&dev_priv->drm.mode_config.connection_mutex));
@@ -4286,10 +4288,16 @@ intel_dp_check_link_status(struct intel_dp *intel_dp) 
		return;

	}



	if (!intel_encoder->base.crtc)

	if (!conn_state->crtc)

		return;



	if (!to_intel_crtc(intel_encoder->base.crtc)->active)

	WARN_ON(!drm_modeset_is_locked(&conn_state->crtc->mutex));



	if (!conn_state->crtc->state->active)

		return;



	if (conn_state->commit &&

	    !try_wait_for_completion(&conn_state->commit->hw_done))

		return;



	/*
@@ -4364,9 +4372,8 @@ intel_dp_short_pulse(struct intel_dp *intel_dp) 
			DRM_DEBUG_DRIVER("CP or sink specific irq unhandled\n");

	}



	drm_modeset_lock(&dev_priv->drm.mode_config.connection_mutex, NULL);

	intel_dp_check_link_status(intel_dp);

	drm_modeset_unlock(&dev_priv->drm.mode_config.connection_mutex);



	if (intel_dp->compliance.test_type == DP_TEST_LINK_TRAINING) {

		DRM_DEBUG_KMS("Link Training Compliance Test requested\n");

		/* Send a Hotplug Uevent to userspace to start modeset */
@@ -4814,8 +4821,19 @@ intel_dp_detect(struct drm_connector *connector, 
		      connector->base.id, connector->name);



	/* If full detect is not performed yet, do a full detect */

	if (!intel_dp->detect_done)

	if (!intel_dp->detect_done) {

		struct drm_crtc *crtc;

		int ret;



		crtc = connector->state->crtc;

		if (crtc) {

			ret = drm_modeset_lock(&crtc->mutex, ctx);

			if (ret)

				return ret;

		}



		status = intel_dp_long_pulse(intel_dp->attached_connector);

	}



	intel_dp->detect_done = false;
@@ -5097,7 +5115,38 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd) 
	}



	if (!intel_dp->is_mst) {

		if (!intel_dp_short_pulse(intel_dp)) {

		struct drm_modeset_acquire_ctx ctx;

		struct drm_connector *connector = &intel_dp->attached_connector->base;

		struct drm_crtc *crtc;

		int iret;

		bool handled = false;



		drm_modeset_acquire_init(&ctx, 0);

retry:

		iret = drm_modeset_lock(&dev_priv->drm.mode_config.connection_mutex, &ctx);

		if (iret)

			goto err;



		crtc = connector->state->crtc;

		if (crtc) {

			iret = drm_modeset_lock(&crtc->mutex, &ctx);

			if (iret)

				goto err;

		}



		handled = intel_dp_short_pulse(intel_dp);



err:

		if (iret == -EDEADLK) {

			drm_modeset_backoff(&ctx);

			goto retry;

		}



		drm_modeset_drop_locks(&ctx);

		drm_modeset_acquire_fini(&ctx);

		WARN(iret, "Acquiring modeset locks failed with %i\n", iret);



		if (!handled) {

			intel_dp->detect_done = false;

			goto put_power;

		}