[Intel-gfx] [PATCH v3 3/6] drm/i915: Check encoder type in enc_to_dig_port()

[Imre Deak]

On Wed, Feb 22, 2017 at 08:34:28AM +0200, Ander Conselvan de Oliveira wrote:
> Don't allow conversion from arbitraty encoder types to a digital port.
> Calling enc_to_dig_port() with the wrong encoder may seem far fetched,
> but certain paths of the ddi code may be called with hasell's analog
> encoder and the conversion is wrong for DP mst encoders too, so safe
> guard against it.
> 
> Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_drv.h | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index a3cf866..2011651 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1121,7 +1121,18 @@ intel_attached_encoder(struct drm_connector *connector)
>  static inline struct intel_digital_port *
>  enc_to_dig_port(struct drm_encoder *encoder)
>  {
> -	return container_of(encoder, struct intel_digital_port, base.base);
> +	struct intel_encoder *intel_encoder = to_intel_encoder(encoder);
> +
> +	switch (intel_encoder->type) {
> +	case INTEL_OUTPUT_DP:
> +	case INTEL_OUTPUT_EDP:
> +	case INTEL_OUTPUT_HDMI:
> +	case INTEL_OUTPUT_UNKNOWN:

Nitpick: for UNKNOWN could've added a WARN_ON(!DDI) check. Either way:
Reviewed-by: Imre Deak <imre.deak at intel.com>

> +		return container_of(encoder, struct intel_digital_port,
> +				    base.base);
> +	default:
> +		return NULL;
> +	}
>  }
>  
>  static inline struct intel_dp_mst_encoder *
> -- 
> 2.9.3
>