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[2/2,SRU,C] drm/i915: Enable hotplug retry

Message ID 20190723073845.21842-3-vicamo.yang@canonical.com
State New
Headers show
Series drm/i915: Fix hotplug issues | expand

Commit Message

You-Sheng Yang July 23, 2019, 7:38 a.m. UTC 
From: José Roberto de Souza <jose.souza@intel.com>

BugLink: http://bugs.launchpad.net/bugs/1835001

Right now we are aware of two cases that needs another hotplug retry:
- Unpowered type-c dongles
- HDMI slow unplug

Both have a complete explanation in the code to schedule another run
of the hotplug handler.

It could have more checks to just trigger the retry in those two
specific cases but why would sink signal a long pulse if there is
no change? Also the drawback of running the hotplug handler again
is really low and that could fix another cases that we are not
aware.

Also retrying for old DP ports(non-DDI) to make it consistent and not
cause CI failures if those systems are connected to chamelium boards
that will be used to simulate the issues reported in here.

v2: Also retrying for old DP ports(non-DDI)(Imre)

v4: Renamed INTEL_HOTPLUG_NOCHANGE to INTEL_HOTPLUG_UNCHANGED to keep
it consistent(Rodrigo)

Tested-by: Timo Aaltonen <tjaalton@ubuntu.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190712005343.24571-2-jose.souza@intel.com
(backported from commit bb80c9255770fa1ed54e889a6bee628bdd0f6762
git://anongit.freedesktop.org/drm-intel)
Signed-off-by: You-Sheng Yang <vicamo.yang@canonical.com>
---
 drivers/gpu/drm/i915/intel_ddi.c  | 21 +++++++++++++++++++++
 drivers/gpu/drm/i915/intel_dp.c   |  7 +++++++
 drivers/gpu/drm/i915/intel_hdmi.c | 28 +++++++++++++++++++++++++++-
 3 files changed, 55 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 2161ce3dc82e..df5e2fb562df 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -3339,6 +3339,7 @@  intel_ddi_hotplug(struct intel_encoder *encoder,
 		  struct intel_connector *connector,
 		  bool irq_received)
 {
+	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;
@@ -3365,6 +3366,26 @@  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 time to those dongles to power up
+	 * and then retrying the probe.
+	 *
+	 * On many platforms the HDMI live state signal is known to be
+	 * unreliable, so we can't use it to detect if a sink is connected or
+	 * not. Instead we detect if it's connected based on whether we can
+	 * read the EDID or not. That in turn has a problem during disconnect,
+	 * since the HPD interrupt may be raised before the DDC lines get
+	 * disconnected (due to how the required length of DDC vs. HPD
+	 * connector pins are specified) and so we'll still be able to get a
+	 * valid EDID. To solve this schedule another detection cycle if this
+	 * time around we didn't detect any change in the sink's connection
+	 * status.
+	 */
+	if (state == INTEL_HOTPLUG_UNCHANGED && irq_received &&
+	    !dig_port->dp.is_mst)
+		state = INTEL_HOTPLUG_RETRY;
+
 	return state;
 }
 
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index ce6e1f3747af..346f6b368f78 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4428,6 +4428,13 @@  intel_dp_hotplug(struct intel_encoder *encoder,
 	drm_modeset_acquire_fini(&ctx);
 	WARN(ret, "Acquiring modeset locks failed with %i\n", ret);
 
+	/*
+	 * Keeping it consistent with intel_ddi_hotplug() and
+	 * intel_hdmi_hotplug().
+	 */
+	if (state == INTEL_HOTPLUG_UNCHANGED && irq_received)
+		state = INTEL_HOTPLUG_RETRY;
+
 	return state;
 }
 
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 79eb57b9c9bf..77149f0db916 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -2367,6 +2367,32 @@  void intel_hdmi_init_connector(struct intel_digital_port *intel_dig_port,
 	}
 }
 
+static enum intel_hotplug_state
+intel_hdmi_hotplug(struct intel_encoder *encoder,
+		   struct intel_connector *connector, bool irq_received)
+{
+	enum intel_hotplug_state state;
+
+	state = intel_encoder_hotplug(encoder, connector, irq_received);
+
+	/*
+	 * On many platforms the HDMI live state signal is known to be
+	 * unreliable, so we can't use it to detect if a sink is connected or
+	 * not. Instead we detect if it's connected based on whether we can
+	 * read the EDID or not. That in turn has a problem during disconnect,
+	 * since the HPD interrupt may be raised before the DDC lines get
+	 * disconnected (due to how the required length of DDC vs. HPD
+	 * connector pins are specified) and so we'll still be able to get a
+	 * valid EDID. To solve this schedule another detection cycle if this
+	 * time around we didn't detect any change in the sink's connection
+	 * status.
+	 */
+	if (state == INTEL_HOTPLUG_UNCHANGED && irq_received)
+		state = INTEL_HOTPLUG_RETRY;
+
+	return state;
+}
+
 void intel_hdmi_init(struct drm_i915_private *dev_priv,
 		     i915_reg_t hdmi_reg, enum port port)
 {
@@ -2390,7 +2416,7 @@  void intel_hdmi_init(struct drm_i915_private *dev_priv,
 			 &intel_hdmi_enc_funcs, DRM_MODE_ENCODER_TMDS,
 			 "HDMI %c", port_name(port));
 
-	intel_encoder->hotplug = intel_encoder_hotplug;
+	intel_encoder->hotplug = intel_hdmi_hotplug;
 	intel_encoder->compute_config = intel_hdmi_compute_config;
 	if (HAS_PCH_SPLIT(dev_priv)) {
 		intel_encoder->disable = pch_disable_hdmi;