drm/i915/display: Fix HPD short pulse handling for eDP

Commit 13ea6db2 ("drm/i915/edp: Ignore short pulse when panel
powered off") completely broke short pulse handling for eDP as it is
usually generated by sink when it is displaying image and there is
some error or status that source needs to handle.

When power panel is enabled, this state is enough to power aux
transactions and VDD override is disabled, so intel_pps_have_power()
is always returning false causing short pulses to be ignored.

So here better naming this function that intends to check if aux
lines are powered to avoid the endless cycle mentioned in the commit
being fixed and fixing the check for what it is intended.

v2:
- renamed to intel_pps_have_panel_power_or_vdd()
- fixed indentation

Fixes: 13ea6db2 ("drm/i915/edp: Ignore short pulse when panel powered off")
Cc: Anshuman Gupta <anshuman.gupta@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220311185149.110527-1-jose.souza@intel.com
(cherry picked from commit 8f0c1c09)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

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

@@ -4863,7 +4863,7 @@ intel_dp_hpd_pulse(struct intel_digital_port *dig_port, bool long_hpd)
 	struct intel_dp *intel_dp = &dig_port->dp;
 
 	if (dig_port->base.type == INTEL_OUTPUT_EDP &&
-	    (long_hpd || !intel_pps_have_power(intel_dp))) {
+	    (long_hpd || !intel_pps_have_panel_power_or_vdd(intel_dp))) {
 		/*
 		 * vdd off can generate a long/short pulse on eDP which
 		 * would require vdd on to handle it, and thus we

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

@@ -1075,13 +1075,13 @@ static void intel_pps_vdd_sanitize(struct intel_dp *intel_dp)
 	edp_panel_vdd_schedule_off(intel_dp);
 }
 
-bool intel_pps_have_power(struct intel_dp *intel_dp)
+bool intel_pps_have_panel_power_or_vdd(struct intel_dp *intel_dp)
 {
 	intel_wakeref_t wakeref;
 	bool have_power = false;
 
 	with_intel_pps_lock(intel_dp, wakeref) {
-		have_power = edp_have_panel_power(intel_dp) &&
+		have_power = edp_have_panel_power(intel_dp) ||
 			     edp_have_panel_vdd(intel_dp);
 	}
 

drivers/gpu/drm/i915/display/intel_pps.h

@@ -37,7 +37,7 @@ void intel_pps_vdd_on(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);
-bool intel_pps_have_power(struct intel_dp *intel_dp);
+bool intel_pps_have_panel_power_or_vdd(struct intel_dp *intel_dp);
 void intel_pps_wait_power_cycle(struct intel_dp *intel_dp);
 
 void intel_pps_init(struct intel_dp *intel_dp);