drm/i915/dp: Avoid joiner for eDP if not enabled in VBT

For eDP, enable the Pipe Joiner feature only if VBT explicitly allows it.
If VBT disables the feature, skip joiner for eDP, even if the hardware
supports it.

Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/14616
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patch.msgid.link/20260108124141.1407760-3-ankit.k.nautiyal@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 053443eea9d50e532aed9e16dce4703bf995e949..79fd3b8d8b253e541d550a6a1e18d78c5043d729 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -494,11 +494,16 @@ bool intel_dp_has_joiner(struct intel_dp *intel_dp)
        struct intel_display *display = to_intel_display(intel_dp);
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct intel_encoder *encoder = &intel_dig_port->base;
+       struct intel_connector *connector = intel_dp->attached_connector;
 
        /* eDP MSO is not compatible with joiner */
        if (intel_dp->mso_link_count)
                return false;
 
+       if (intel_dp_is_edp(intel_dp) &&
+           !connector->panel.vbt.edp.pipe_joiner_enable)
+               return false;
+
        return DISPLAY_VER(display) >= 12 ||
                (DISPLAY_VER(display) == 11 &&
                 encoder->port != PORT_A);