Some unpowered USB type-c dongles requires some time to power on
before being able to process aux channel transactions.
It was not a problem 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, causing sinks to not be detected.
So here it test if DP type-c port is responsive before proceed with
hotplug sequence, it try 5 times with a 150ms of delay between tries
before giving up.
If unpowered TBT dongles shows up in the market this approach should
be extended to TBT ports too.
Signed-off-by: José Roberto de Souza <jose.souza@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_drv.h | 1 +
drivers/gpu/drm/i915/intel_ddi.c | 4 +
drivers/gpu/drm/i915/intel_drv.h | 2 +
drivers/gpu/drm/i915/intel_hotplug.c | 108 +++++++++++++++++++++++++++
4 files changed, 115 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 03db011caa8e..3fd8c3fa6515 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2639,6 +2639,7 @@ enum hpd_pin intel_hpd_pin_default(struct drm_i915_private *dev_priv,
enum port port);
bool intel_hpd_disable(struct drm_i915_private *dev_priv, enum hpd_pin pin);
void intel_hpd_enable(struct drm_i915_private *dev_priv, enum hpd_pin pin);
+void intel_hotplug_tc_wa_work(struct work_struct *work);
/* i915_irq.c */
static inline void i915_queue_hangcheck(struct drm_i915_private *dev_priv)
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index b0bb8dfc2ed5..2c149843cacf 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -4258,6 +4258,10 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
goto err;
intel_dig_port->hpd_pulse = intel_dp_hpd_pulse;
+
+ if (IS_ICELAKE(dev_priv) && intel_port_is_tc(dev_priv, port))
+ INIT_DELAYED_WORK(&intel_dig_port->tc_wa_work,
+ intel_hotplug_tc_wa_work);
}
/* In theory we don't need the encoder->type check, but leave it just in
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 33b733d37706..fbb6f78ce733 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1242,6 +1242,8 @@ struct intel_digital_port {
enum intel_display_power_domain ddi_io_power_domain;
bool tc_legacy_port:1;
enum tc_port_type tc_type;
+ struct delayed_work tc_wa_work;
+ u8 tc_wa_count;
void (*write_infoframe)(struct intel_encoder *encoder,
const struct intel_crtc_state *crtc_state,
diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c
index e027d2b4abe5..9838b60e8f63 100644
--- a/drivers/gpu/drm/i915/intel_hotplug.c
+++ b/drivers/gpu/drm/i915/intel_hotplug.c
@@ -342,6 +342,74 @@ static void i915_digport_work_func(struct work_struct *work)
}
}
+#define TC_WA_DELAY_MSEC 150
+#define TC_WA_TRIES 5
+
+/*
+ * Test if type-c dongle is responsive return true if so otherwise schedule a
+ * work to try again and return false.
+ */
+static bool intel_hotplug_tc_wa_test(struct intel_digital_port *dig_port)
+{
+ struct intel_dp *intel_dp = &dig_port->dp;
+ u8 buffer;
+
+ dig_port->tc_wa_count++;
+
+ if (drm_dp_dpcd_read(&intel_dp->aux, DP_DPCD_REV, &buffer, 1) != 1)
+ goto not_responsive;
+
+ if (!drm_probe_ddc(&intel_dp->aux.ddc))
+ goto not_responsive;
+
+ return true;
+
+not_responsive:
+ if (dig_port->tc_wa_count < TC_WA_TRIES) {
+ const unsigned long delay = msecs_to_jiffies(TC_WA_DELAY_MSEC);
+
+ schedule_delayed_work(&dig_port->tc_wa_work, delay);
+ } else {
+ DRM_DEBUG_KMS("TC port not responsive, giving up\n");
+ }
+
+ return false;
+}
+
+void intel_hotplug_tc_wa_work(struct work_struct *work)
+{
+ struct delayed_work *delayed_work = to_delayed_work(work);
+ struct intel_digital_port *dig_port = container_of(delayed_work,
+ struct intel_digital_port,
+ tc_wa_work);
+ struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
+ struct intel_encoder *intel_encoder = &dig_port->base;
+ struct intel_dp *intel_dp = &dig_port->dp;
+ struct intel_connector *intel_connector = intel_dp->attached_connector;
+ struct drm_device *dev = &dev_priv->drm;
+ intel_wakeref_t wakeref;
+ bool ret;
+
+ wakeref = intel_runtime_pm_get(dev_priv);
+
+ if (!intel_digital_port_connected(intel_encoder) ||
+ dig_port->tc_type != TC_PORT_TYPEC) {
+ intel_runtime_pm_put(dev_priv, wakeref);
+ return;
+ }
+
+ mutex_lock(&dev->mode_config.mutex);
+ ret = intel_hotplug_tc_wa_test(dig_port);
+ if (ret)
+ ret = intel_encoder->hotplug(intel_encoder, intel_connector);
+ mutex_unlock(&dev->mode_config.mutex);
+
+ if (ret)
+ drm_kms_helper_hotplug_event(dev);
+
+ intel_runtime_pm_put(dev_priv, wakeref);
+}
+
/*
* Handle hotplug events outside the interrupt handler proper.
*/
@@ -377,9 +445,37 @@ static void i915_hotplug_work_func(struct work_struct *work)
continue;
intel_encoder = intel_connector->encoder;
if (hpd_event_bits & (1 << intel_encoder->hpd_pin)) {
+ struct intel_digital_port *dig_port = enc_to_dig_port(&intel_encoder->base);
+
DRM_DEBUG_KMS("Connector %s (pin %i) received hotplug event.\n",
connector->name, intel_encoder->hpd_pin);
+ /*
+ * Type-C dongles WA: Unpowered type-C dongles can take
+ * some time to be responsible, so let's try to do a
+ * DPCD read to check if it is ready, otherwise skip
+ * the call to the hotplug callback and schedule a work
+ * to try a DPCD read again after a few micro-seconds.
+ */
+ if (IS_ICELAKE(dev_priv) &&
+ intel_port_is_tc(dev_priv, intel_encoder->port)) {
+ intel_wakeref_t wakeref;
+ bool skip_hotplug = false;
+
+ wakeref = intel_runtime_pm_get(dev_priv);
+
+ if (intel_digital_port_connected(intel_encoder) &&
+ dig_port->tc_type == TC_PORT_TYPEC) {
+ dig_port->tc_wa_count = 0;
+ skip_hotplug = !intel_hotplug_tc_wa_test(dig_port);
+ }
+
+ intel_runtime_pm_put(dev_priv, wakeref);
+
+ if (skip_hotplug)
+ continue;
+ }
+
changed |= intel_encoder->hotplug(intel_encoder,
intel_connector);
}
@@ -644,6 +740,8 @@ void intel_hpd_init_work(struct drm_i915_private *dev_priv)
void intel_hpd_cancel_work(struct drm_i915_private *dev_priv)
{
+ struct intel_encoder *encoder;
+
spin_lock_irq(&dev_priv->irq_lock);
dev_priv->hotplug.long_port_mask = 0;
@@ -656,6 +754,16 @@ void intel_hpd_cancel_work(struct drm_i915_private *dev_priv)
cancel_work_sync(&dev_priv->hotplug.hotplug_work);
cancel_work_sync(&dev_priv->hotplug.poll_init_work);
cancel_delayed_work_sync(&dev_priv->hotplug.reenable_work);
+
+ for_each_intel_encoder(&dev_priv->drm, encoder) {
+ struct intel_digital_port *dig_port;
+
+ dig_port = enc_to_dig_port(&encoder->base);
+ /* tc_wa_work is only initialized for TC with DP ports */
+ if (IS_ICELAKE(dev_priv) && dig_port && dig_port->hpd_pulse)
+ cancel_delayed_work_sync(&dig_port->tc_wa_work);
+ }
+
}
bool intel_hpd_disable(struct drm_i915_private *dev_priv, enum hpd_pin pin)
--
2.20.1
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