drm/i915/dpcd_bl: Unbreak enable_dpcd_backlight modparam

BugLink: https://bugs.launchpad.net/bugs/1898865
Looks like I accidentally made it so you couldn't force DPCD backlight
support on, whoops. Fix that.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Fixes: 17f5d57915be ("drm/i915: Force DPCD backlight mode on X1 Extreme 2nd Gen 4K AMOLED panel")
Cc: Adam Jackson <ajax@redhat.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200413214407.1851002-1-lyude@redhat.com
(cherry picked from commit d082119f4277ff4a63e44d293864aa9f2112b217)
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
index af6ee93aaed4897a26e927cdc0a9e36b04f9474f..50abd2afc1330c3373f1463a46b6b95dc39bcb81 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -339,6 +339,7 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector)
         */
        if (dev_priv->vbt.backlight.type !=
            INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE &&
+           i915_modparams.enable_dpcd_backlight != 1 &&
            !drm_dp_has_quirk(&intel_dp->desc, intel_dp->edid_quirks,
                              DP_QUIRK_FORCE_DPCD_BACKLIGHT)) {
                DRM_DEV_INFO(dev->dev,