drm/i915: check connector->encoder before using it.

DP MST will need connectors that aren't connected to specific
encoders, add some checks in advance to avoid oopses.

Reviewed-by: Todd Previte <tprevite@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

3 files changed, 27 insertions, 18 deletions

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 4a5b0f80e059..f27daf70ba72 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2209,13 +2209,15 @@ static void intel_connector_info(struct seq_file *m,
                 seq_printf(m, "\tCEA rev: %d\n",
                            connector->display_info.cea_rev);
         }
-        if (intel_encoder->type == INTEL_OUTPUT_DISPLAYPORT ||
-            intel_encoder->type == INTEL_OUTPUT_EDP)
-                intel_dp_info(m, intel_connector);
-        else if (intel_encoder->type == INTEL_OUTPUT_HDMI)
-                intel_hdmi_info(m, intel_connector);
-        else if (intel_encoder->type == INTEL_OUTPUT_LVDS)
-                intel_lvds_info(m, intel_connector);
+        if (intel_encoder) {
+                if (intel_encoder->type == INTEL_OUTPUT_DISPLAYPORT ||
+                    intel_encoder->type == INTEL_OUTPUT_EDP)
+                        intel_dp_info(m, intel_connector);
+                else if (intel_encoder->type == INTEL_OUTPUT_HDMI)
+                        intel_hdmi_info(m, intel_connector);
+                else if (intel_encoder->type == INTEL_OUTPUT_LVDS)
+                        intel_lvds_info(m, intel_connector);
+        }
 
         seq_printf(m, "\tmodes:\n");
         list_for_each_entry(mode, &connector->modes, head)
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 026f0a3f3b90..12d77b5368c4 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1165,6 +1165,8 @@ static void i915_hotplug_work_func(struct work_struct *work)
         dev_priv->hpd_event_bits = 0;
         list_for_each_entry(connector, &mode_config->connector_list, head) {
                 intel_connector = to_intel_connector(connector);
+                if (!intel_connector->encoder)
+                        continue;
                 intel_encoder = intel_connector->encoder;
                 if (intel_encoder->hpd_pin > HPD_NONE &&
                     dev_priv->hpd_stats[intel_encoder->hpd_pin].hpd_mark == HPD_MARK_DISABLED &&
@@ -1195,6 +1197,8 @@ static void i915_hotplug_work_func(struct work_struct *work)
 
         list_for_each_entry(connector, &mode_config->connector_list, head) {
                 intel_connector = to_intel_connector(connector);
+                if (!intel_connector->encoder)
+                        continue;
                 intel_encoder = intel_connector->encoder;
                 if (hpd_event_bits & (1 << intel_encoder->hpd_pin)) {
                         if (intel_encoder->hot_plug)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index e07e6b5dee35..008bb3dc88cb 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5003,20 +5003,23 @@ static void intel_connector_check_state(struct intel_connector *connector)
                      "wrong connector dpms state\n");
                 WARN(connector->base.encoder != &encoder->base,
                      "active connector not linked to encoder\n");
-                WARN(!encoder->connectors_active,
-                     "encoder->connectors_active not set\n");
 
-                encoder_enabled = encoder->get_hw_state(encoder, &pipe);
-                WARN(!encoder_enabled, "encoder not enabled\n");
-                if (WARN_ON(!encoder->base.crtc))
-                        return;
+                if (encoder) {
+                        WARN(!encoder->connectors_active,
+                             "encoder->connectors_active not set\n");
+
+                        encoder_enabled = encoder->get_hw_state(encoder, &pipe);
+                        WARN(!encoder_enabled, "encoder not enabled\n");
+                        if (WARN_ON(!encoder->base.crtc))
+                                return;
 
-                crtc = encoder->base.crtc;
+                        crtc = encoder->base.crtc;
 
-                WARN(!crtc->enabled, "crtc not enabled\n");
-                WARN(!to_intel_crtc(crtc)->active, "crtc not active\n");
-                WARN(pipe != to_intel_crtc(crtc)->pipe,
-                     "encoder active on the wrong pipe\n");
+                        WARN(!crtc->enabled, "crtc not enabled\n");
+                        WARN(!to_intel_crtc(crtc)->active, "crtc not active\n");
+                        WARN(pipe != to_intel_crtc(crtc)->pipe,
+                             "encoder active on the wrong pipe\n");
+                }
         }
 }