[Intel-gfx] [PATCH v2 09/10] drm/i915: Unify error handling for missing DDI buf trans tables

[James Ausmus]

On Wed, Oct 18, 2017 at 09:19:34PM +0300, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Handle missing buf trans tables, or out of bounds buf trans levels
> the same way everywhere. These should never be hit under normal
> conditions, but let's play it safe for now.
> 
> v2: Avoid the hdmi_level=-1 case (James)
> 
> Cc: James Ausmus <james.ausmus at intel.com>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Reviewed-by: James Ausmus <james.ausmus at intel.com>

> ---
>  drivers/gpu/drm/i915/intel_ddi.c | 27 ++++++++++++++++++++++-----
>  1 file changed, 22 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> index 5ee0e33e2c00..cd7a0d979a10 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -801,6 +801,11 @@ static int intel_ddi_hdmi_level(struct drm_i915_private *dev_priv, enum port por
>  	    hdmi_level >= n_hdmi_entries)
>  		hdmi_level = hdmi_default_entry;
>  
> +	if (WARN_ON_ONCE(n_hdmi_entries == 0))
> +		return 0;
> +	if (WARN_ON_ONCE(hdmi_level >= n_hdmi_entries))
> +		hdmi_level = n_hdmi_entries - 1;
> +
>  	return hdmi_level;
>  }
>  
> @@ -864,6 +869,11 @@ static void intel_prepare_hdmi_ddi_buffers(struct intel_encoder *encoder,
>  
>  	ddi_translations_hdmi = intel_ddi_get_buf_trans_hdmi(dev_priv, &n_hdmi_entries);
>  
> +	if (WARN_ON_ONCE(!ddi_translations_hdmi))
> +		return;
> +	if (WARN_ON_ONCE(hdmi_level >= n_hdmi_entries))
> +		hdmi_level = n_hdmi_entries - 1;
> +
>  	/* If we're boosting the current, set bit 31 of trans1 */
>  	if (IS_GEN9_BC(dev_priv) &&
>  	    dev_priv->vbt.ddi_port_info[port].hdmi_boost_level)
> @@ -1847,6 +1857,11 @@ static void skl_ddi_set_iboost(struct intel_encoder *encoder,
>  		else
>  			ddi_translations = intel_ddi_get_buf_trans_dp(dev_priv, port, &n_entries);
>  
> +		if (WARN_ON_ONCE(!ddi_translations))
> +			return;
> +		if (WARN_ON_ONCE(level >= n_entries))
> +			level = n_entries - 1;
> +
>  		iboost = ddi_translations[level].i_boost;
>  	}
>  
> @@ -1877,6 +1892,11 @@ static void bxt_ddi_vswing_sequence(struct intel_encoder *encoder,
>  	else
>  		ddi_translations = bxt_get_buf_trans_dp(dev_priv, &n_entries);
>  
> +	if (WARN_ON_ONCE(!ddi_translations))
> +		return;
> +	if (WARN_ON_ONCE(level >= n_entries))
> +		level = n_entries - 1;
> +
>  	bxt_ddi_phy_set_signal_level(dev_priv, port,
>  				     ddi_translations[level].margin,
>  				     ddi_translations[level].scale,
> @@ -1932,13 +1952,10 @@ static void cnl_ddi_vswing_program(struct intel_encoder *encoder,
>  	else
>  		ddi_translations = cnl_get_buf_trans_dp(dev_priv, &n_entries);
>  
> -	if (WARN_ON(ddi_translations == NULL))
> +	if (WARN_ON_ONCE(!ddi_translations))
>  		return;
> -
> -	if (level >= n_entries) {
> -		DRM_DEBUG_KMS("DDI translation not found for level %d. Using %d instead.", level, n_entries - 1);
> +	if (WARN_ON_ONCE(level >= n_entries))
>  		level = n_entries - 1;
> -	}
>  
>  	/* Set PORT_TX_DW5 Scaling Mode Sel to 010b. */
>  	val = I915_READ(CNL_PORT_TX_DW5_LN0(port));
> -- 
> 2.13.6
>