drm/i915/sdvo: If we have an EDID confirm it matches the mode of the connection

If we have an EDID for a digital panel, but we are probing a non-TMDS
connector then we know that this is a false detection, and vice versa.
This should reduce the number of bogus outputs on multi-function
adapters that report the same output on multiple connectors.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=34101
Reported-by: Sebastien Caty <sebastien.caty@mrnf.gouv.qc.ca>
Tested-by: Sebastien Caty <sebastien.caty@mrnf.gouv.qc.ca>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org

1 files changed, 27 insertions, 5 deletions

diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index 6a09c1413d60..d2dd90a9a101 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -46,6 +46,7 @@
                          SDVO_TV_MASK)
 
 #define IS_TV(c)        (c->output_flag & SDVO_TV_MASK)
+#define IS_TMDS(c)      (c->output_flag & SDVO_TMDS_MASK)
 #define IS_LVDS(c)      (c->output_flag & SDVO_LVDS_MASK)
 #define IS_TV_OR_LVDS(c) (c->output_flag & (SDVO_TV_MASK | SDVO_LVDS_MASK))
 
@@ -1359,7 +1360,8 @@ intel_sdvo_hdmi_sink_detect(struct drm_connector *connector)
                                 intel_sdvo->has_hdmi_monitor = drm_detect_hdmi_monitor(edid);
                                 intel_sdvo->has_hdmi_audio = drm_detect_monitor_audio(edid);
                         }
-                }
+                } else
+                        status = connector_status_disconnected;
                 connector->display_info.raw_edid = NULL;
                 kfree(edid);
         }
@@ -1407,10 +1409,25 @@ intel_sdvo_detect(struct drm_connector *connector, bool force)
 
         if ((intel_sdvo_connector->output_flag & response) == 0)
                 ret = connector_status_disconnected;
-        else if (response & SDVO_TMDS_MASK)
+        else if (IS_TMDS(intel_sdvo_connector))
                 ret = intel_sdvo_hdmi_sink_detect(connector);
-        else
-                ret = connector_status_connected;
+        else {
+                struct edid *edid;
+
+                /* if we have an edid check it matches the connection */
+                edid = intel_sdvo_get_edid(connector);
+                if (edid == NULL)
+                        edid = intel_sdvo_get_analog_edid(connector);
+                if (edid != NULL) {
+                        if (edid->input & DRM_EDID_INPUT_DIGITAL)
+                                ret = connector_status_disconnected;
+                        else
+                                ret = connector_status_connected;
+                        connector->display_info.raw_edid = NULL;
+                        kfree(edid);
+                } else
+                        ret = connector_status_connected;
+        }
 
         /* May update encoder flag for like clock for SDVO TV, etc.*/
         if (ret == connector_status_connected) {
@@ -1446,10 +1463,15 @@ static void intel_sdvo_get_ddc_modes(struct drm_connector *connector)
                 edid = intel_sdvo_get_analog_edid(connector);
 
         if (edid != NULL) {
-                if (edid->input & DRM_EDID_INPUT_DIGITAL) {
+                struct intel_sdvo_connector *intel_sdvo_connector = to_intel_sdvo_connector(connector);
+                bool monitor_is_digital = !!(edid->input & DRM_EDID_INPUT_DIGITAL);
+                bool connector_is_digital = !!IS_TMDS(intel_sdvo_connector);
+
+                if (connector_is_digital == monitor_is_digital) {
                         drm_mode_connector_update_edid_property(connector, edid);
                         drm_add_edid_modes(connector, edid);
                 }
+
                 connector->display_info.raw_edid = NULL;
                 kfree(edid);
         }