On TypeC ports if a sink deasserts/reasserts its HPD signal, generating a hotplug interrupt without the sink getting unplugged/replugged from the connector, there can be an up to 3 seconds delay until the AUX channel gets functional. To avoid detection failures this delay causes retry the detection for 5 seconds.
I noticed this on ICL/TGL RVPs and a DELL XPS 13 7390 ICL laptop. References: https://gitlab.freedesktop.org/drm/intel/issues/1067 Signed-off-by: Imre Deak <[email protected]> --- drivers/gpu/drm/i915/display/intel_ddi.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c index 4f508bf70f3b..2d947ff83488 100644 --- a/drivers/gpu/drm/i915/display/intel_ddi.c +++ b/drivers/gpu/drm/i915/display/intel_ddi.c @@ -4371,7 +4371,10 @@ static enum intel_hotplug_state intel_ddi_hotplug(struct intel_encoder *encoder, struct intel_connector *connector) { + struct drm_i915_private *i915 = to_i915(encoder->base.dev); struct intel_digital_port *dig_port = enc_to_dig_port(encoder); + enum phy phy = intel_port_to_phy(i915, encoder->port); + bool is_tc = intel_phy_is_tc(i915, phy); struct drm_modeset_acquire_ctx ctx; enum intel_hotplug_state state; int ret; @@ -4414,8 +4417,15 @@ intel_ddi_hotplug(struct intel_encoder *encoder, * valid EDID. To solve this schedule another detection cycle if this * time around we didn't detect any change in the sink's connection * status. + * + * Type-c connectors which get their HPD signal deasserted then + * reasserted, without unplugging/replugging the sink from the + * connector, introduce a delay until the AUX channel communication + * becomes functional. Retry the detection for 5 seconds on type-c + * connectors to account for this delay. */ - if (state == INTEL_HOTPLUG_UNCHANGED && !connector->hotplug_retries && + if (state == INTEL_HOTPLUG_UNCHANGED && + connector->hotplug_retries < (is_tc ? 5 : 1) && !dig_port->dp.is_mst) state = INTEL_HOTPLUG_RETRY; -- 2.23.1 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
