diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 58f4b02151f200f9cc96b70a81dad79a66f98d95..33aaad30c0bc70b930f6824d49e4cd5a5bc3d3a1 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -9530,6 +9530,19 @@ static void i915_disable_vga(struct drm_device *dev) POSTING_READ(vga_reg); } +static void ivb_pch_pwm_override(struct drm_device *dev) +{ + struct drm_i915_private *dev_priv = dev->dev_private; + + /* + * IVB has CPU eDP backlight regs too, set things up to let the + * PCH regs control the backlight + */ + I915_WRITE(BLC_PWM_CPU_CTL2, PWM_ENABLE); + I915_WRITE(BLC_PWM_CPU_CTL, 0); + I915_WRITE(BLC_PWM_PCH_CTL1, PWM_ENABLE | (1<<30)); +} + void intel_modeset_init_hw(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; @@ -9545,6 +9558,9 @@ void intel_modeset_init_hw(struct drm_device *dev) gen6_enable_rps(dev_priv); gen6_update_ring_freq(dev_priv); } + + if (IS_IVYBRIDGE(dev)) + ivb_pch_pwm_override(dev); } void intel_modeset_init(struct drm_device *dev)