[Intel-gfx] [PATCH 02/11] drm/i915: Fix vbt PWM max setup for CTG

[Jani Nikula]

On Mon, 30 Nov 2015, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> CTG uses hrawclk for backlight, so calculate the max based on that
> instead of cdclk.

If you say so.

Acked-by: Jani Nikula <jani.nikula at intel.com>

> Fixes: aa17cdb4f836 ("drm/i915: initialize backlight max from VBT")
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_panel.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
> index ea528ca854e8..737e12349e81 100644
> --- a/drivers/gpu/drm/i915/intel_panel.c
> +++ b/drivers/gpu/drm/i915/intel_panel.c
> @@ -1344,13 +1344,19 @@ static u32 i9xx_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
>  
>  /*
>   * Gen4: This value represents the period of the PWM stream in display core
> - * clocks multiplied by 128.
> + * clocks ([DevCTG] HRAW clocks) multiplied by 128.
> + *
>   */
>  static u32 i965_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
>  {
>  	struct drm_device *dev = connector->base.dev;
>  	struct drm_i915_private *dev_priv = dev->dev_private;
> -	int clock = 1000 * dev_priv->display.get_display_clock_speed(dev);
> +	int clock;
> +
> +	if (IS_G4X(dev_priv))
> +		clock = MHz(intel_hrawclk(dev));
> +	else
> +		clock = 1000 * dev_priv->display.get_display_clock_speed(dev);
>  
>  	return clock / (pwm_freq_hz * 128);
>  }

-- 
Jani Nikula, Intel Open Source Technology Center