drv/i915: Pull display_clock_mode out of VBT table

BugLink: http://bugs.launchpad.net/bugs/614238

This tells the driver whether a CK505 clock source is available on
pre-PCH hardware. If so, it should be used as the non-SSC source,
leaving the internal clock for use as the SSC source.

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Chris Wison <chris@chris-wilson.co.uk>
(cherry picked from commit abd06860185fc613776adae792772e076d77caf2)

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Herton Krzesinski <herton.krzesinski@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>

3 files changed, 8 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 4fd4350d04b..5c2d4c74b76 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -357,6 +357,7 @@ typedef struct drm_i915_private {
         unsigned int lvds_vbt:1;
         unsigned int int_crt_support:1;
         unsigned int lvds_use_ssc:1;
+        unsigned int display_clock_mode:1;
         int lvds_ssc_freq;
         struct {
                 int rate;
diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index bdac1a8cbae..70361fcee41 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -285,11 +285,13 @@ parse_general_features(struct drm_i915_private *dev_priv,
                 dev_priv->lvds_use_ssc = general->enable_ssc;
                 dev_priv->lvds_ssc_freq =
                         intel_bios_ssc_frequency(dev, general->ssc_freq);
-                DRM_DEBUG_KMS("BDB_GENERAL_FEATURES int_tv_support %d int_crt_support %d lvds_use_ssc %d lvds_ssc_freq %d\n",
+                dev_priv->display_clock_mode = general->display_clock_mode;
+                DRM_DEBUG_KMS("BDB_GENERAL_FEATURES int_tv_support %d int_crt_support %d lvds_use_ssc %d lvds_ssc_freq %d display_clock_mode %d\n",
                               dev_priv->int_tv_support,
                               dev_priv->int_crt_support,
                               dev_priv->lvds_use_ssc,
-                              dev_priv->lvds_ssc_freq);
+                              dev_priv->lvds_ssc_freq,
+                              dev_priv->display_clock_mode);
         }
 }
 
diff --git a/drivers/gpu/drm/i915/intel_bios.h b/drivers/gpu/drm/i915/intel_bios.h
index 5f8e4edcbbb..02b1b62415d 100644
--- a/drivers/gpu/drm/i915/intel_bios.h
+++ b/drivers/gpu/drm/i915/intel_bios.h
@@ -120,7 +120,9 @@ struct bdb_general_features {
         u8 ssc_freq:1;
         u8 enable_lfp_on_override:1;
         u8 disable_ssc_ddt:1;
-        u8 rsvd8:3; /* finish byte */
+        u8 rsvd7:1;
+        u8 display_clock_mode:1;
+        u8 rsvd8:1; /* finish byte */
 
         /* bits 3 */
         u8 disable_smooth_vision:1;