drm/i915: default to having backlight if VBT not available

Apparently there are Apple laptops with magic smoke for a VBIOS, which
we fail to find and use. Default to having and setting up backlight in
this case.

This fixes a regression introduced by
commit c675949ec58ca50d5a3ae3c757892f1560f6e896
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Wed Apr 9 11:31:37 2014 +0300

    drm/i915: do not setup backlight if not available according to VBT

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=77831
Reported-and-tested-by: Matteo Cypriani <mcy@lm7.fr>
Cc: stable@vger.kernel.org # 3.15+
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index 1ee98f121a00fbe4be26cf60187d9b7a81983caf..827498e081df545df16ecbe308f93210ae05582c 100644 (file)
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -315,9 +315,6 @@ parse_lfp_backlight(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
        const struct bdb_lfp_backlight_data *backlight_data;
        const struct bdb_lfp_backlight_data_entry *entry;
 
-       /* Err to enabling backlight if no backlight block. */
-       dev_priv->vbt.backlight.present = true;
-
        backlight_data = find_section(bdb, BDB_LVDS_BACKLIGHT);
        if (!backlight_data)
                return;
@@ -1088,6 +1085,9 @@ init_vbt_defaults(struct drm_i915_private *dev_priv)
 
        dev_priv->vbt.crt_ddc_pin = GMBUS_PORT_VGADDC;
 
+       /* Default to having backlight */
+       dev_priv->vbt.backlight.present = true;
+
        /* LFP panel data */
        dev_priv->vbt.lvds_dither = 1;
        dev_priv->vbt.lvds_vbt = 0;