From: Imre Deak Date: Tue, 20 Feb 2024 21:18:40 +0000 (+0200) Subject: drm/i915/dp: Read DPRX for all long HPD pulses X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=a32f3a95413881b69c8dd319334927eb9519013c;p=linux.git drm/i915/dp: Read DPRX for all long HPD pulses The TBT DP tunnel BW request logic in the Thunderbolt Connection Manager depends on the GFX driver reading out the sink's DPRX capabilities in response to a long HPD pulse. Since in i915 this read-out can be blocked by another connector's/encoder's hotplug event handling (which is serialized by drm_mode_config::connection_mutex), do a dummy DPRX read-out in the encoder's HPD pulse handler (which is not blocked by other encoders). Reviewed-by: Uma Shankar Reviewed-by: Ville Syrjälä Signed-off-by: Imre Deak Link: https://patchwork.freedesktop.org/patch/msgid/20240220211841.448846-21-imre.deak@intel.com --- diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 0b9c33a000f95..a0e826a740b13 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -6165,6 +6165,7 @@ intel_dp_hpd_pulse(struct intel_digital_port *dig_port, bool long_hpd) { struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev); struct intel_dp *intel_dp = &dig_port->dp; + u8 dpcd[DP_RECEIVER_CAP_SIZE]; if (dig_port->base.type == INTEL_OUTPUT_EDP && (long_hpd || !intel_pps_have_panel_power_or_vdd(intel_dp))) { @@ -6187,6 +6188,17 @@ intel_dp_hpd_pulse(struct intel_digital_port *dig_port, bool long_hpd) dig_port->base.base.name, long_hpd ? "long" : "short"); + /* + * TBT DP tunnels require the GFX driver to read out the DPRX caps in + * response to long HPD pulses. The DP hotplug handler does that, + * however the hotplug handler may be blocked by another + * connector's/encoder's hotplug handler. Since the TBT CM may not + * complete the DP tunnel BW request for the latter connector/encoder + * waiting for this encoder's DPRX read, perform a dummy read here. + */ + if (long_hpd) + intel_dp_read_dprx_caps(intel_dp, dpcd); + if (long_hpd) { intel_dp->reset_link_params = true; return IRQ_NONE;