Re: [PATCH 1/4] drm/i915/dp: split up panel power control from backlight pwm control

[Clint Taylor <clinton.a.taylor@intel.com>]

On 08/12/2014 07:11 AM, Jani Nikula wrote:
> Make it possible to change panel power control backlight state without
> touching the PWM. No functional changes.
>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>   drivers/gpu/drm/i915/intel_dp.c | 39 ++++++++++++++++++++++++++-------------
>   1 file changed, 26 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index e5ada4fbe945..d8baf60ff3fd 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -1384,7 +1384,8 @@ void intel_edp_panel_off(struct intel_dp *intel_dp)
>   	intel_display_power_put(dev_priv, power_domain);
>   }
>
> -void intel_edp_backlight_on(struct intel_dp *intel_dp)
> +/* Enable backlight in the panel power control. */
> +static void _intel_edp_backlight_on(struct intel_dp *intel_dp)
>   {
>   	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
>   	struct drm_device *dev = intel_dig_port->base.base.dev;
> @@ -1392,13 +1393,6 @@ void intel_edp_backlight_on(struct intel_dp *intel_dp)
>   	u32 pp;
>   	u32 pp_ctrl_reg;
>
> -	if (!is_edp(intel_dp))
> -		return;
> -
> -	DRM_DEBUG_KMS("\n");
> -
> -	intel_panel_enable_backlight(intel_dp->attached_connector);
> -
>   	/*
>   	 * If we enable the backlight right away following a panel power
>   	 * on, we may see slight flicker as the panel syncs with the eDP
> @@ -1415,17 +1409,26 @@ void intel_edp_backlight_on(struct intel_dp *intel_dp)
>   	POSTING_READ(pp_ctrl_reg);
>   }
>
> -void intel_edp_backlight_off(struct intel_dp *intel_dp)
> +/* Enable backlight PWM and backlight PP control. */
> +void intel_edp_backlight_on(struct intel_dp *intel_dp)
> +{
> +	if (!is_edp(intel_dp))
> +		return;
> +
> +	DRM_DEBUG_KMS("\n");
> +
> +	intel_panel_enable_backlight(intel_dp->attached_connector);
> +	_intel_edp_backlight_on(intel_dp);
> +}
> +
> +/* Disable backlight in the panel power control. */
> +static void _intel_edp_backlight_off(struct intel_dp *intel_dp)
>   {
>   	struct drm_device *dev = intel_dp_to_dev(intel_dp);
>   	struct drm_i915_private *dev_priv = dev->dev_private;
>   	u32 pp;
>   	u32 pp_ctrl_reg;
>
> -	if (!is_edp(intel_dp))
> -		return;
> -
> -	DRM_DEBUG_KMS("\n");
>   	pp = ironlake_get_pp_control(intel_dp);
>   	pp &= ~EDP_BLC_ENABLE;
>
> @@ -1436,7 +1439,17 @@ void intel_edp_backlight_off(struct intel_dp *intel_dp)
>   	intel_dp->last_backlight_off = jiffies;
>
>   	edp_wait_backlight_off(intel_dp);
> +}
> +
> +/* Disable backlight PP control and backlight PWM. */
> +void intel_edp_backlight_off(struct intel_dp *intel_dp)
> +{
> +	if (!is_edp(intel_dp))
> +		return;
> +
> +	DRM_DEBUG_KMS("\n");
>
> +	_intel_edp_backlight_off(intel_dp);
>   	intel_panel_disable_backlight(intel_dp->attached_connector);
>   }
>
>

Patch works as expected.

Some day we need to rename intel_panel_disable_backlight() to 
intel_panel_disable_backlight_pwm() to make this code more readable as 
all intel_panel_backlight_ methods only affect the PWM.

Clint