[Intel-gfx] [PATCH v2] drm/i915: Check backlight type while doing eDP backlight initializaiton

[Jani Nikula]

On Wed, 19 Jun 2019, Lee Shawn C <shawn.c.lee at intel.com> wrote:
> If LFP backlight type setting from VBT was "VESA eDP AUX Interface".
> Driver should check panel capability and try to initialize aux backlight.
> No matter i915_modparams.enable_dpcd_backlight was enabled or not.
>
> v2: access dev_priv->vbt.backlight.type directly and remove unused function.
>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Cc: Jani Nikula <jani.nikula at intel.com>
> Cc: Jose Roberto de Souza <jose.souza at intel.com>
> Cc: Cooper Chiou <cooper.chiou at intel.com>
>
> Signed-off-by: Lee Shawn C <shawn.c.lee at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_bios.h             | 1 +
>  drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 4 +++-
>  2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_bios.h b/drivers/gpu/drm/i915/display/intel_bios.h
> index 4e42cfaf61a7..0b7be6389a07 100644
> --- a/drivers/gpu/drm/i915/display/intel_bios.h
> +++ b/drivers/gpu/drm/i915/display/intel_bios.h
> @@ -42,6 +42,7 @@ enum intel_backlight_type {
>  	INTEL_BACKLIGHT_DISPLAY_DDI,
>  	INTEL_BACKLIGHT_DSI_DCS,
>  	INTEL_BACKLIGHT_PANEL_DRIVER_INTERFACE,
> +	INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE,
>  };
>  
>  struct edp_power_seq {
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> index 7ded95a334db..db7c7b9f9b56 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> @@ -264,8 +264,10 @@ intel_dp_aux_display_control_capable(struct intel_connector *connector)
>  int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector)
>  {
>  	struct intel_panel *panel = &intel_connector->panel;
> +	struct drm_i915_private *dev_priv = to_i915(intel_connector->base.dev);
>  
> -	if (!i915_modparams.enable_dpcd_backlight)
> +	if (!i915_modparams.enable_dpcd_backlight &&
> +	    (dev_priv->vbt.backlight.type != INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE))
>  		return -ENODEV;

There was also this part in the v1 review:

    The usual thing to do is to set i915.enable_dpcd_backlight initial value
    to -1 (i.e. make it an int), and with that default value respect
    VBT. Otherwise, respect the value of enable_dpcd_backlight.


BR,
Jani.



>  
>  	if (!intel_dp_aux_display_control_capable(intel_connector))

-- 
Jani Nikula, Intel Open Source Graphics Center