drm/i915/mso: using joiner is not possible with eDP MSO

It's not possible to use the joiner at the same time with eDP MSO. When
a panel needs MSO, it's not optional, so MSO trumps joiner.

v3: Only change intel_dp_has_joiner(), leave debugfs alone (Ville)

Fixes: bc71194e8897 ("drm/i915/edp: enable eDP MSO during link training")
Cc: <stable@vger.kernel.org> # v5.13+
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/1668
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240614142311.589089-1-jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 53b26c354f3834c5d94c5317b5e562388e010f91..3903f6ead6e6602daba0e26917ebbd6d8005afbf 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -465,6 +465,10 @@ bool intel_dp_has_joiner(struct intel_dp *intel_dp)
        struct intel_encoder *encoder = &intel_dig_port->base;
        struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
 
+       /* eDP MSO is not compatible with joiner */
+       if (intel_dp->mso_link_count)
+               return false;
+
        return DISPLAY_VER(dev_priv) >= 12 ||
                (DISPLAY_VER(dev_priv) == 11 &&
                 encoder->port != PORT_A);