[Intel-gfx] [PATCH] drm/i915: Eliminate lots of WARNs when there's no backlight present

[Jani Nikula]

On Thu, 16 Jan 2014, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> My 855gm doesn't register the intel backlight but it still ends up
> calling the backlight code to enable/disable the backlight via the
> LVDS code. This leads to some WARNs due to backlight.max being 0.
>
> Let's have intel_panel_enable_backlight() and intel_panel_disable_backlight()
> check whether there's a backlight present or not.
>
> Also move the backlight.present check from asle_set_backlight() into
> intel_panel_set_backlight() for some extra symmetry.

I have an identical patch in my local repo dated Dec 13... should've
sent it out weeks ago. Damn.

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

> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_opregion.c | 10 ++--------
>  drivers/gpu/drm/i915/intel_panel.c    |  6 +++---
>  2 files changed, 5 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c
> index 3da259e..37e9a96 100644
> --- a/drivers/gpu/drm/i915/intel_opregion.c
> +++ b/drivers/gpu/drm/i915/intel_opregion.c
> @@ -396,9 +396,7 @@ int intel_opregion_notify_adapter(struct drm_device *dev, pci_power_t state)
>  static u32 asle_set_backlight(struct drm_device *dev, u32 bclp)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
> -	struct drm_connector *connector;
>  	struct intel_connector *intel_connector;
> -	struct intel_panel *panel;
>  	struct opregion_asle __iomem *asle = dev_priv->opregion.asle;
>  
>  	DRM_DEBUG_DRIVER("bclp = 0x%08x\n", bclp);
> @@ -417,12 +415,8 @@ static u32 asle_set_backlight(struct drm_device *dev, u32 bclp)
>  	 * only one).
>  	 */
>  	DRM_DEBUG_KMS("updating opregion backlight %d/255\n", bclp);
> -	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
> -		intel_connector = to_intel_connector(connector);
> -		panel = &intel_connector->panel;
> -		if (panel->backlight.present)
> -			intel_panel_set_backlight(intel_connector, bclp, 255);
> -	}
> +	list_for_each_entry(intel_connector, &dev->mode_config.connector_list, base.head)
> +		intel_panel_set_backlight(intel_connector, bclp, 255);
>  	iowrite32(DIV_ROUND_UP(bclp * 100, 255) | ASLE_CBLV_VALID, &asle->cblv);
>  
>  	mutex_unlock(&dev->mode_config.mutex);
> diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
> index 20ebc3e..350de35 100644
> --- a/drivers/gpu/drm/i915/intel_panel.c
> +++ b/drivers/gpu/drm/i915/intel_panel.c
> @@ -502,7 +502,7 @@ void intel_panel_set_backlight(struct intel_connector *connector, u32 level,
>  	u32 freq;
>  	unsigned long flags;
>  
> -	if (pipe == INVALID_PIPE)
> +	if (!panel->backlight.present || pipe == INVALID_PIPE)
>  		return;
>  
>  	spin_lock_irqsave(&dev_priv->backlight_lock, flags);
> @@ -579,7 +579,7 @@ void intel_panel_disable_backlight(struct intel_connector *connector)
>  	enum pipe pipe = intel_get_pipe_from_connector(connector);
>  	unsigned long flags;
>  
> -	if (pipe == INVALID_PIPE)
> +	if (!panel->backlight.present || pipe == INVALID_PIPE)
>  		return;
>  
>  	/*
> @@ -782,7 +782,7 @@ void intel_panel_enable_backlight(struct intel_connector *connector)
>  	enum pipe pipe = intel_get_pipe_from_connector(connector);
>  	unsigned long flags;
>  
> -	if (pipe == INVALID_PIPE)
> +	if (!panel->backlight.present || pipe == INVALID_PIPE)
>  		return;
>  
>  	DRM_DEBUG_KMS("pipe %c\n", pipe_name(pipe));
> -- 
> 1.8.3.2
>
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-- 
Jani Nikula, Intel Open Source Technology Center