From: Ville Syrjälä <ville.syrj...@linux.intel.com> Jani wanted some comments to explain why we call certain vdd on/off functions in certain places.
v2: Make the comments more thorough (Imre) Reviewed-by: Imre Deak <imre.d...@intel.com> Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com> --- drivers/gpu/drm/i915/intel_dp.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index e28610f..d8e868a 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1349,6 +1349,11 @@ static u32 ironlake_get_pp_control(struct intel_dp *intel_dp) return control; } +/* + * Must be paired with edp_panel_vdd_off(). + * Must hold pps_mutex around the whole on/off sequence. + * Can be nested with intel_edp_panel_vdd_{on,off}() calls. + */ static bool edp_panel_vdd_on(struct intel_dp *intel_dp) { struct drm_device *dev = intel_dp_to_dev(intel_dp); @@ -1399,6 +1404,13 @@ static bool edp_panel_vdd_on(struct intel_dp *intel_dp) return need_to_disable; } +/* + * Must be paired with intel_edp_panel_vdd_off() or + * intel_edp_panel_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. + */ void intel_edp_panel_vdd_on(struct intel_dp *intel_dp) { bool vdd; @@ -1477,6 +1489,11 @@ static void edp_panel_vdd_schedule_off(struct intel_dp *intel_dp) schedule_delayed_work(&intel_dp->panel_vdd_work, delay); } +/* + * Must be paired with edp_panel_vdd_on(). + * Must hold pps_mutex around the whole on/off sequence. + * Can be nested with intel_edp_panel_vdd_{on,off}() calls. + */ static void edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync) { struct drm_i915_private *dev_priv = @@ -1497,6 +1514,12 @@ static void edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync) edp_panel_vdd_schedule_off(intel_dp); } +/* + * Must be paired with intel_edp_panel_vdd_on(). + * 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. + */ static void intel_edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync) { if (!is_edp(intel_dp)) @@ -4390,6 +4413,10 @@ void intel_dp_encoder_destroy(struct drm_encoder *encoder) drm_encoder_cleanup(encoder); if (is_edp(intel_dp)) { cancel_delayed_work_sync(&intel_dp->panel_vdd_work); + /* + * vdd might still be enabled do to the delayed vdd off. + * Make sure vdd is actually turned off here. + */ pps_lock(intel_dp); edp_panel_vdd_off_sync(intel_dp); pps_unlock(intel_dp); @@ -4409,6 +4436,10 @@ static void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder) if (!is_edp(intel_dp)) return; + /* + * vdd might still be enabled do to the delayed vdd off. + * Make sure vdd is actually turned off here. + */ pps_lock(intel_dp); edp_panel_vdd_off_sync(intel_dp); pps_unlock(intel_dp); @@ -5116,6 +5147,10 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port, drm_dp_aux_unregister(&intel_dp->aux); if (is_edp(intel_dp)) { cancel_delayed_work_sync(&intel_dp->panel_vdd_work); + /* + * vdd might still be enabled do to the delayed vdd off. + * Make sure vdd is actually turned off here. + */ pps_lock(intel_dp); edp_panel_vdd_off_sync(intel_dp); pps_unlock(intel_dp); -- 1.8.5.5 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx