drm/i915/dp: Ensure panel power remains enabled during connector detection

The sink's capabilities, like the DSC caps, depend on the source OUI
written to the sink's DPCD registers and so this OUI value should be
valid for the whole duration of the detection. An eDP sink will reset
this OUI value when the panel power is disabled, so prevent the
disabling - happening by default after a 1 sec idle period - for the
whole duration of detection.

v2: Update the documentation for intel_pps_on(). (Jani)

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241025160259.3088727-3-imre.deak@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index a19ecb845a78d2634354721c439edf395ae80381..b86ede9a1aa5734f30c48300921cba8bd01dc123 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5619,6 +5619,8 @@ intel_dp_detect(struct drm_connector *connector,
 
        intel_dp_flush_connector_commits(intel_connector);
 
+       intel_pps_vdd_on(intel_dp);
+
        /* Can't disconnect eDP */
        if (intel_dp_is_edp(intel_dp))
                status = edp_detect(intel_dp);
@@ -5649,12 +5651,15 @@ intel_dp_detect(struct drm_connector *connector,
 
                intel_dp_tunnel_disconnect(intel_dp);
 
-               goto out;
+               goto out_unset_edid;
        }
 
        ret = intel_dp_tunnel_detect(intel_dp, ctx);
-       if (ret == -EDEADLK)
-               return ret;
+       if (ret == -EDEADLK) {
+               status = ret;
+
+               goto out_vdd_off;
+       }
 
        if (ret == 1)
                intel_connector->base.epoch_counter++;
@@ -5682,7 +5687,7 @@ intel_dp_detect(struct drm_connector *connector,
                 * with EDID on it
                 */
                status = connector_status_disconnected;
-               goto out;
+               goto out_unset_edid;
        }
 
        /*
@@ -5711,7 +5716,7 @@ intel_dp_detect(struct drm_connector *connector,
 
        intel_dp_check_device_service_irq(intel_dp);
 
-out:
+out_unset_edid:
        if (status != connector_status_connected && !intel_dp->is_mst)
                intel_dp_unset_edid(intel_dp);
 
@@ -5720,6 +5725,9 @@ out:
                                                 status,
                                                 intel_dp->dpcd,
                                                 intel_dp->downstream_ports);
+out_vdd_off:
+       intel_pps_vdd_off(intel_dp);
+
        return status;
 }
 

diff --git a/drivers/gpu/drm/i915/display/intel_pps.c b/drivers/gpu/drm/i915/display/intel_pps.c
index 0bd8e4de8b697fcdab17f03ad29aa224f0004d6b..a1b2c400d6a54881fc01957b63031b5061685205 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_pps.c
+++ b/drivers/gpu/drm/i915/display/intel_pps.c
@@ -797,7 +797,8 @@ bool intel_pps_vdd_on_unlocked(struct intel_dp *intel_dp)
 }
 
 /*
- * Must be paired with intel_pps_off().
+ * Must be paired with intel_pps_vdd_off() or - to disable
+ * both VDD and panel power - intel_pps_off().
  * Nested calls to these functions are not allowed since
  * we drop the lock. Caller must use some higher level
  * locking to prevent nested calls from other threads.
@@ -944,6 +945,17 @@ void intel_pps_vdd_off_unlocked(struct intel_dp *intel_dp, bool sync)
                edp_panel_vdd_schedule_off(intel_dp);
 }
 
+void intel_pps_vdd_off(struct intel_dp *intel_dp)
+{
+       intel_wakeref_t wakeref;
+
+       if (!intel_dp_is_edp(intel_dp))
+               return;
+
+       with_intel_pps_lock(intel_dp, wakeref)
+               intel_pps_vdd_off_unlocked(intel_dp, false);
+}
+
 void intel_pps_on_unlocked(struct intel_dp *intel_dp)
 {
        struct intel_display *display = to_intel_display(intel_dp);

diff --git a/drivers/gpu/drm/i915/display/intel_pps.h b/drivers/gpu/drm/i915/display/intel_pps.h
index bc5046d5362647a37e83876bfa1a122b0bdf033c..c83007152f07dc8c915684d431c967b6f0e29266 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_pps.h
+++ b/drivers/gpu/drm/i915/display/intel_pps.h
@@ -34,6 +34,7 @@ void intel_pps_off_unlocked(struct intel_dp *intel_dp);
 void intel_pps_check_power_unlocked(struct intel_dp *intel_dp);
 
 void intel_pps_vdd_on(struct intel_dp *intel_dp);
+void intel_pps_vdd_off(struct intel_dp *intel_dp);
 void intel_pps_on(struct intel_dp *intel_dp);
 void intel_pps_off(struct intel_dp *intel_dp);
 void intel_pps_vdd_off_sync(struct intel_dp *intel_dp);