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

commit 56c4b63aaf4c2cd91966b2a5e69e5367bea60bbe upstream.

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>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index aff4a113cda3c0cd724d3b4d13ce0fb8bbc48313..7eda7440d776e7995eacc9f3317e553044c40278 100644 (file)
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -287,9 +287,6 @@ 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;
@@ -839,6 +836,9 @@ 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;