diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c index 858c959f7bab..f735b035436c 100644 --- a/drivers/gpu/drm/i915/display/intel_bios.c +++ b/drivers/gpu/drm/i915/display/intel_bios.c @@ -3540,6 +3540,27 @@ enum aux_ch intel_bios_dp_aux_ch(const struct intel_bios_encoder_data *devdata) return map_aux_ch(devdata->i915, devdata->child.aux_channel); } +bool intel_bios_dp_has_shared_aux_ch(const struct intel_bios_encoder_data *devdata) +{ + struct drm_i915_private *i915; + u8 aux_channel; + int count = 0; + + if (!devdata || !devdata->child.aux_channel) + return false; + + i915 = devdata->i915; + aux_channel = devdata->child.aux_channel; + + list_for_each_entry(devdata, &i915->display.vbt.display_devices, node) { + if (intel_bios_encoder_supports_dp(devdata) && + aux_channel == devdata->child.aux_channel) + count++; + } + + return count > 1; +} + int intel_bios_dp_boost_level(const struct intel_bios_encoder_data *devdata) { if (!devdata || devdata->i915->display.vbt.version < 196 || !devdata->child.iboost) diff --git a/drivers/gpu/drm/i915/display/intel_bios.h b/drivers/gpu/drm/i915/display/intel_bios.h index 9680e3e92bb5..49e24b7cf675 100644 --- a/drivers/gpu/drm/i915/display/intel_bios.h +++ b/drivers/gpu/drm/i915/display/intel_bios.h @@ -273,6 +273,7 @@ enum aux_ch intel_bios_dp_aux_ch(const struct intel_bios_encoder_data *devdata); int intel_bios_dp_boost_level(const struct intel_bios_encoder_data *devdata); int intel_bios_dp_max_lane_count(const struct intel_bios_encoder_data *devdata); int intel_bios_dp_max_link_rate(const struct intel_bios_encoder_data *devdata); +bool intel_bios_dp_has_shared_aux_ch(const struct intel_bios_encoder_data *devdata); int intel_bios_hdmi_boost_level(const struct intel_bios_encoder_data *devdata); int intel_bios_hdmi_ddc_pin(const struct intel_bios_encoder_data *devdata); int intel_bios_hdmi_level_shift(const struct intel_bios_encoder_data *devdata); diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 12bd2f322e62..e0e4cb529284 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -5512,8 +5512,13 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, /* * VBT and straps are liars. Also check HPD as that seems * to be the most reliable piece of information available. + * + * ... expect on devices that forgot to hook HPD up for eDP + * (eg. Acer Chromebook C710), so we'll check it only if multiple + * ports are attempting to use the same AUX CH, according to VBT. */ - if (!intel_digital_port_connected(encoder)) { + if (intel_bios_dp_has_shared_aux_ch(encoder->devdata) && + !intel_digital_port_connected(encoder)) { /* * If this fails, presume the DPCD answer came * from some other port using the same AUX CH.