[Intel-gfx] [PATCH 1/2] drm/i915: check VBT for supported backlight type

[Ville Syrjälä]

On Wed, Apr 09, 2014 at 01:35:34PM +0300, Jani Nikula wrote:
> The only supported types are none and PWM. Other values are obsolete or
> reserved, don't add them.
> 
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h   |    1 +
>  drivers/gpu/drm/i915/intel_bios.c |   10 ++++++++++
>  drivers/gpu/drm/i915/intel_bios.h |    3 +++
>  3 files changed, 14 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 55addaaa8222..03f4c866bf3e 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1154,6 +1154,7 @@ struct intel_vbt_data {
>  	struct edp_power_seq edp_pps;
>  
>  	struct {
> +		bool present;
>  		u16 pwm_freq_hz;
>  		bool active_low_pwm;

Could pack the bools next to each other.

Otherwise the series looks good. Obviously I can't tell whether the VBT
can be trusted on this, but at least the code matches the spec I have.

So for the series:
Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

>  	} backlight;
> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> index 9b986775c4b0..862ca04f7a44 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -309,6 +309,9 @@ parse_lfp_backlight(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
>  	const struct bdb_lfp_backlight_data *backlight_data;
>  	const struct bdb_lfp_backlight_data_entry *entry;
>  
> +	/* Err to enabling backlight if no backlight block. */
> +	dev_priv->vbt.backlight.present = true;
> +
>  	backlight_data = find_section(bdb, BDB_LVDS_BACKLIGHT);
>  	if (!backlight_data)
>  		return;
> @@ -321,6 +324,13 @@ parse_lfp_backlight(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
>  
>  	entry = &backlight_data->data[panel_type];
>  
> +	dev_priv->vbt.backlight.present = entry->type == BDB_BACKLIGHT_TYPE_PWM;
> +	if (!dev_priv->vbt.backlight.present) {
> +		DRM_DEBUG_KMS("PWM backlight not present in VBT (type %u)\n",
> +			      entry->type);
> +		return;
> +	}
> +
>  	dev_priv->vbt.backlight.pwm_freq_hz = entry->pwm_freq_hz;
>  	dev_priv->vbt.backlight.active_low_pwm = entry->active_low_pwm;
>  	DRM_DEBUG_KMS("VBT backlight PWM modulation frequency %u Hz, "
> diff --git a/drivers/gpu/drm/i915/intel_bios.h b/drivers/gpu/drm/i915/intel_bios.h
> index d02e5f93c362..036a79922391 100644
> --- a/drivers/gpu/drm/i915/intel_bios.h
> +++ b/drivers/gpu/drm/i915/intel_bios.h
> @@ -389,6 +389,9 @@ struct bdb_lvds_lfp_data {
>  	struct bdb_lvds_lfp_data_entry data[16];
>  } __packed;
>  
> +#define BDB_BACKLIGHT_TYPE_NONE	0
> +#define BDB_BACKLIGHT_TYPE_PWM	2
> +
>  struct bdb_lfp_backlight_data_entry {
>  	u8 type:2;
>  	u8 active_low_pwm:1;
> -- 
> 1.7.9.5
> 
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-- 
Ville Syrjälä
Intel OTC