[Intel-gfx] [PATCH 2/2] drm/i915/icl: Probe again type-c connectors that failed

[José Roberto de Souza]

Unpowered type-c dongles can take some time to boot and be
responsible, causing the probe to fail and sink never be detected
without further actions from userspace.

It was not a issue for older platforms because there was a hardware
bridge between DDI/DP ports and type-c controller adding a implicit
delay that hid this issue but ICL have type-c controllers integrated
to the SOC bring this issue to users.

So here if the probe failed when coming from a IRQ it returns
INTEL_HOTPLUG_RETRY that will schedule another run of
i915_hotplug_work_func() after 1 second what is time enough for
those type-c dongles to boot.

Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Imre Deak <imre.deak at intel.com>
Cc: Jani Nikula <jani.nikula at intel.com>
Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
---
 drivers/gpu/drm/i915/intel_ddi.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 1676a87f18cb..96bbcf5c9787 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -4056,6 +4056,8 @@ intel_ddi_hotplug(struct intel_encoder *encoder,
 		  struct intel_connector *connector,
 		  bool irq_received)
 {
+	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+	struct intel_digital_port *dig_port = enc_to_dig_port(&encoder->base);
 	struct drm_modeset_acquire_ctx ctx;
 	enum intel_hotplug_state state;
 	int ret;
@@ -4082,6 +4084,17 @@ intel_ddi_hotplug(struct intel_encoder *encoder,
 	drm_modeset_acquire_fini(&ctx);
 	WARN(ret, "Acquiring modeset locks failed with %i\n", ret);
 
+	/*
+	 * Unpowered type-c dongles can take some time to boot and be
+	 * responsible, so here giving some type to those dongles to power up
+	 * and then retrying the probe.
+	 */
+	if (state == INTEL_HOTPLUG_NOCHANGE &&
+	    connector->base.status != connector_status_connected &&
+	    irq_received && intel_port_is_tc(dev_priv, encoder->port) &&
+	    !dig_port->tc_legacy_port && !dig_port->dp.is_mst)
+		state = INTEL_HOTPLUG_RETRY;
+
 	return state;
 }
 
-- 
2.20.1