drm/i915: spt does not have pch backlight override bit

SPT is always in the PCH override mode, and the bit MBZ. Only set
override on LPT.

v2: check for PCH version (Ville)

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index e3def5a..e18b3f4 100644 (file)
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -775,8 +775,9 @@ static void bdw_enable_backlight(struct intel_connector *connector)
        if (panel->backlight.active_low_pwm)
                pch_ctl1 |= BLM_PCH_POLARITY;
 
-       /* BDW always uses the pch pwm controls. */
-       pch_ctl1 |= BLM_PCH_OVERRIDE_ENABLE;
+       /* After LPT, override is the default. */
+       if (HAS_PCH_LPT(dev_priv))
+               pch_ctl1 |= BLM_PCH_OVERRIDE_ENABLE;
 
        I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1);
        POSTING_READ(BLC_PWM_PCH_CTL1);