[Intel-gfx] [RFC 5/5] drm/i915: Work queue for uevent

[Manasi Navare]

We create a work queue for sending a hotplug uevent. This
gets scheduled on link training failure and gets executed after
modeset is finished and all locks are released.
This was required to avoid deadlock.

Cc: Jani Nikula <jani.nikula at linux.intel.com>
Cc: Daniel Vetter <daniel.vetter at intel.com>
Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h |  2 ++
 drivers/gpu/drm/i915/intel_dp.c | 12 ++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index a219a35..9592e64 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1962,6 +1962,8 @@ struct drm_i915_private {
 
 	struct drm_i915_gem_object *vlv_pctx;
 
+	struct work_struct i915_modeset_retry_work;
+
 #ifdef CONFIG_DRM_FBDEV_EMULATION
 	/* list of fbdev register on this device */
 	struct intel_fbdev *fbdev;
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 4779742..9c1944a 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -5716,6 +5716,15 @@ out_vdd_off:
 	return false;
 }
 
+static void intel_dp_modeset_retry_work_fn(struct work_struct *work)
+{
+	struct drm_i915_private *dev_priv;
+
+	dev_priv = container_of(work, typeof(*dev_priv), i915_modeset_retry_work);
+	DRM_DEBUG_KMS("\nManasi: Sending Uevent");
+	drm_kms_helper_hotplug_event(&dev_priv->drm);
+}
+
 bool
 intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
 			struct intel_connector *intel_connector)
@@ -5728,6 +5737,9 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
 	enum port port = intel_dig_port->port;
 	int type;
 
+	/* Initialize the work for modeset in case of link train failure */
+	INIT_WORK(&dev_priv->i915_modeset_retry_work, intel_dp_modeset_retry_work_fn);
+
 	if (WARN(intel_dig_port->max_lanes < 1,
 		 "Not enough lanes (%d) for DP on port %c\n",
 		 intel_dig_port->max_lanes, port_name(port)))
-- 
1.9.1