1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index f9c5f17af9d8..464d8ad9bb71 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4498,6 +4498,18 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
         if (intel_dig_port->base.type != INTEL_OUTPUT_EDP)
                 intel_dig_port->base.type = INTEL_OUTPUT_DISPLAYPORT;
 
+        if (long_hpd && intel_dig_port->base.type == INTEL_OUTPUT_EDP) {
+                /*
+                 * vdd off can generate a long pulse on eDP which
+                 * would require vdd on to handle it, and thus we
+                 * would end up in an endless cycle of
+                 * "vdd off -> long hpd -> vdd on -> detect -> vdd off -> ..."
+                 */
+                DRM_DEBUG_KMS("ignoring long hpd on eDP port %c\n",
+                              port_name(intel_dig_port->port));
+                return false;
+        }
+
         DRM_DEBUG_KMS("got hpd irq on port %c - %s\n",
                       port_name(intel_dig_port->port),
                       long_hpd ? "long" : "short");