Re: [PATCH] drm/i915: Add breadcrumbs for why the backlight is being set

[Jani Nikula <jani.nikula@linux.intel.com>]

On Sun, 13 Oct 2013, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> At the moment we have 3 paths that lead to actually_set_backlight(),
> from modesetting, ACPI/OpRegion requests and our very own
> intel_backlight interface, and we have no way of distinguishing them in
> the debug log. So add a debug breadcrumb to explain the source of the
> backlight changes.
>
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/intel_opregion.c | 1 +
>  drivers/gpu/drm/i915/intel_panel.c    | 4 ++++
>  2 files changed, 5 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c
> index 2acf5cae20e4..564da613b278 100644
> --- a/drivers/gpu/drm/i915/intel_opregion.c
> +++ b/drivers/gpu/drm/i915/intel_opregion.c
> @@ -405,6 +405,7 @@ static u32 asle_set_backlight(struct drm_device *dev, u32 bclp)
>  	if (bclp > 255)
>  		return ASLC_BACKLIGHT_FAILED;
>  
> +	DRM_DEBUG_KMS("updating opregion backlight %d/255\n", bclp);

Just a few lines earliner we have:

	DRM_DEBUG_DRIVER("bclp = 0x%08x\n", bclp);

Other than that,

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


>  	intel_panel_set_backlight(dev, bclp, 255);
>  	iowrite32(DIV_ROUND_UP(bclp * 100, 255) | ASLE_CBLV_VALID, &asle->cblv);
>  
> diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
> index 54684168de1e..1f2996031ad9 100644
> --- a/drivers/gpu/drm/i915/intel_panel.c
> +++ b/drivers/gpu/drm/i915/intel_panel.c
> @@ -574,6 +574,8 @@ void intel_panel_enable_backlight(struct drm_device *dev,
>  		intel_pipe_to_cpu_transcoder(dev_priv, pipe);
>  	unsigned long flags;
>  
> +	DRM_DEBUG_KMS("pipe=%d\n", pipe);
> +
>  	spin_lock_irqsave(&dev_priv->backlight.lock, flags);
>  
>  	if (dev_priv->backlight.level == 0) {
> @@ -680,6 +682,8 @@ intel_panel_detect(struct drm_device *dev)
>  static int intel_panel_update_status(struct backlight_device *bd)
>  {
>  	struct drm_device *dev = bl_get_data(bd);
> +	DRM_DEBUG_KMS("updating intel_backlight, brightness=%d/%d\n",
> +		      bd->props.brightness, bd->props.max_brightness);
>  	intel_panel_set_backlight(dev, bd->props.brightness,
>  				  bd->props.max_brightness);
>  	return 0;
> -- 
> 1.8.4.rc3
>
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-- 
Jani Nikula, Intel Open Source Technology Center