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authorImre Deak <imre.deak@intel.com>2024-02-20 23:18:40 +0200
committerImre Deak <imre.deak@intel.com>2024-02-27 17:35:12 +0200
commita32f3a95413881b69c8dd319334927eb9519013c (patch)
tree83d69c09e834780e03cd8397d01470852bd6945a
parentfb687904aae27c8bf5b5f653c0bf72171bd43b41 (diff)
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 <uma.shankar@intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20240220211841.448846-21-imre.deak@intel.com
-rw-r--r--drivers/gpu/drm/i915/display/intel_dp.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 0b9c33a000f9..a0e826a740b1 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;