Re: [PATCH 14/15] drm/i915: don't count cpu ports for fdi B/C lane sharing

[Imre Deak <imre.deak@intel.com>]

On Fri, 2013-04-19 at 11:24 +0200, Daniel Vetter wrote:
> This allows us to use all 4 fdi lanes on fdi B when the cpu eDP is
> running on pipe C. Yay!
> 
> v2: Encapsulate test into a little helper function, as suggested by
> Chris Wilson.
> 
> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Reviewed-by: Imre Deak <imre.deak@intel.com>

> ---
>  drivers/gpu/drm/i915/intel_display.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 6bcb196..c25dbdd 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -2381,6 +2381,11 @@ static void intel_fdi_normal_train(struct drm_crtc *crtc)
>  			   FDI_FE_ERRC_ENABLE);
>  }
>  
> +static bool pipe_has_enabled_pch(struct intel_crtc *intel_crtc)
> +{
> +	return intel_crtc->base.enabled && intel_crtc->config.has_pch_encoder;
> +}
> +
>  static void ivb_modeset_global_resources(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
> @@ -2390,10 +2395,13 @@ static void ivb_modeset_global_resources(struct drm_device *dev)
>  		to_intel_crtc(dev_priv->pipe_to_crtc_mapping[PIPE_C]);
>  	uint32_t temp;
>  
> -	/* When everything is off disable fdi C so that we could enable fdi B
> -	 * with all lanes. XXX: This misses the case where a pipe is not using
> -	 * any pch resources and so doesn't need any fdi lanes. */
> -	if (!pipe_B_crtc->base.enabled && !pipe_C_crtc->base.enabled) {
> +	/*
> +	 * When everything is off disable fdi C so that we could enable fdi B
> +	 * with all lanes. Note that we don't care about enabled pipes without
> +	 * an enabled pch encoder.
> +	 */
> +	if (!pipe_has_enabled_pch(pipe_B_crtc) &&
> +	    !pipe_has_enabled_pch(pipe_C_crtc)) {
>  		WARN_ON(I915_READ(FDI_RX_CTL(PIPE_B)) & FDI_RX_ENABLE);
>  		WARN_ON(I915_READ(FDI_RX_CTL(PIPE_C)) & FDI_RX_ENABLE);
>  
> @@ -3996,7 +4004,7 @@ static bool ironlake_check_fdi_lanes(struct drm_device *dev, enum pipe pipe,
>  		}
>  		return true;
>  	case PIPE_C:
> -		if (!pipe_B_crtc->base.enabled ||
> +		if (!pipe_has_enabled_pch(pipe_B_crtc) ||
>  		    pipe_B_crtc->config.fdi_lanes <= 2) {
>  			if (pipe_config->fdi_lanes > 2) {
>  				DRM_DEBUG_KMS("invalid shared fdi lane config on pipe %i: %i lanes\n",