Commit 5f8be911 authored by Anshuman Gupta's avatar Anshuman Gupta Committed by Jani Nikula
Browse files

drm/i915/pps: Reuse POWER_DOMAIN_DISPLAY_CORE in pps_{lock, unlock} 



We need a power_domain wakeref in pps_{lock,unlock} to prevent
a race while resetting pps state in intel_power_sequencer_reset().

intel_power_sequencer_reset() need a pps_mutex to access pps_pipe
but it can't grab pps_mutex due to deadlock with power_well
functions are called while holding pps_mutex.
intel_power_sequencer_reset() is called by power_well function
associated with legacy platforms like vlv and chv therefore re-use
the POWER_DOMAIN_DISPLAY_CORE power domain, which only used
by vlv and chv display power domain.

This will avoids the unnecessary noise of unrelated power wells
in pps_{lock,unlock}.

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: default avatarAnshuman Gupta <anshuman.gupta@intel.com>
Reviewed-by: default avatarJani Nikula <jani.nikula@intel.com>
Acked-by: default avatarImre Deak <imre.deak@intel.com>
Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210107112500.16216-1-anshuman.gupta@intel.com
parent 10205618

drivers/gpu/drm/i915/display/intel_dp.c

+2 −6
Original line number Diff line number Diff line
@@ -895,9 +895,7 @@ pps_lock(struct intel_dp *intel_dp) 
	 * See intel_power_sequencer_reset() why we need

	 * a power domain reference here.

	 */

	wakeref = intel_display_power_get(dev_priv,

					  intel_aux_power_domain(dp_to_dig_port(intel_dp)));



	wakeref = intel_display_power_get(dev_priv, POWER_DOMAIN_DISPLAY_CORE);

	mutex_lock(&dev_priv->pps_mutex);



	return wakeref;
@@ -909,9 +907,7 @@ pps_unlock(struct intel_dp *intel_dp, intel_wakeref_t wakeref) 
	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);



	mutex_unlock(&dev_priv->pps_mutex);

	intel_display_power_put(dev_priv,

				intel_aux_power_domain(dp_to_dig_port(intel_dp)),

				wakeref);

	intel_display_power_put(dev_priv, POWER_DOMAIN_DISPLAY_CORE, wakeref);

	return 0;

}