[Intel-gfx] [PATCH] drm/i915: Check lane sharing between pipes B & C using atomic state

[Daniel Vetter]

On Mon, Mar 30, 2015 at 08:33:12AM +0300, Ander Conselvan de Oliveira wrote:
> Makes that code atomic ready.
> 
> v2: Acquire crtc_state for the "other" pipe only when needed. (Daniel)
> 
> v3: Really only acquire the other state if necessary. (Daniel)

Missing sob added and queued for -next, thanks for the patch.
-Daniel
> ---
>  drivers/gpu/drm/i915/intel_display.c | 69 ++++++++++++++++++++++--------------
>  1 file changed, 42 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 75955fe..cfe34c3 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -5667,65 +5667,80 @@ bool intel_connector_get_hw_state(struct intel_connector *connector)
>  	return encoder->get_hw_state(encoder, &pipe);
>  }
>  
> -static int pipe_required_fdi_lanes(struct drm_device *dev, enum pipe pipe)
> +static int pipe_required_fdi_lanes(struct intel_crtc_state *crtc_state)
>  {
> -	struct intel_crtc *crtc =
> -		to_intel_crtc(intel_get_crtc_for_pipe(dev, pipe));
> -
> -	if (crtc->base.state->enable &&
> -	    crtc->config->has_pch_encoder)
> -		return crtc->config->fdi_lanes;
> +	if (crtc_state->base.enable && crtc_state->has_pch_encoder)
> +		return crtc_state->fdi_lanes;
>  
>  	return 0;
>  }
>  
> -static bool ironlake_check_fdi_lanes(struct drm_device *dev, enum pipe pipe,
> +static int ironlake_check_fdi_lanes(struct drm_device *dev, enum pipe pipe,
>  				     struct intel_crtc_state *pipe_config)
>  {
> +	struct drm_atomic_state *state = pipe_config->base.state;
> +	struct intel_crtc *other_crtc;
> +	struct intel_crtc_state *other_crtc_state;
> +
>  	DRM_DEBUG_KMS("checking fdi config on pipe %c, lanes %i\n",
>  		      pipe_name(pipe), pipe_config->fdi_lanes);
>  	if (pipe_config->fdi_lanes > 4) {
>  		DRM_DEBUG_KMS("invalid fdi lane config on pipe %c: %i lanes\n",
>  			      pipe_name(pipe), pipe_config->fdi_lanes);
> -		return false;
> +		return -EINVAL;
>  	}
>  
>  	if (IS_HASWELL(dev) || IS_BROADWELL(dev)) {
>  		if (pipe_config->fdi_lanes > 2) {
>  			DRM_DEBUG_KMS("only 2 lanes on haswell, required: %i lanes\n",
>  				      pipe_config->fdi_lanes);
> -			return false;
> +			return -EINVAL;
>  		} else {
> -			return true;
> +			return 0;
>  		}
>  	}
>  
>  	if (INTEL_INFO(dev)->num_pipes == 2)
> -		return true;
> +		return 0;
>  
>  	/* Ivybridge 3 pipe is really complicated */
>  	switch (pipe) {
>  	case PIPE_A:
> -		return true;
> +		return 0;
>  	case PIPE_B:
> -		if (pipe_config->fdi_lanes > 2 &&
> -		    pipe_required_fdi_lanes(dev, PIPE_C) > 0) {
> +		if (pipe_config->fdi_lanes <= 2)
> +			return 0;
> +
> +		other_crtc = to_intel_crtc(intel_get_crtc_for_pipe(dev, PIPE_C));
> +		other_crtc_state =
> +			intel_atomic_get_crtc_state(state, other_crtc);
> +		if (IS_ERR(other_crtc_state))
> +			return PTR_ERR(other_crtc_state);
> +
> +		if (pipe_required_fdi_lanes(other_crtc_state) > 0) {
>  			DRM_DEBUG_KMS("invalid shared fdi lane config on pipe %c: %i lanes\n",
>  				      pipe_name(pipe), pipe_config->fdi_lanes);
> -			return false;
> +			return -EINVAL;
>  		}
> -		return true;
> +		return 0;
>  	case PIPE_C:
>  		if (pipe_config->fdi_lanes > 2) {
>  			DRM_DEBUG_KMS("only 2 lanes on pipe %c: required %i lanes\n",
>  				      pipe_name(pipe), pipe_config->fdi_lanes);
> -			return false;
> +			return -EINVAL;
>  		}
> -		if (pipe_required_fdi_lanes(dev, PIPE_B) > 2) {
> +
> +		other_crtc = to_intel_crtc(intel_get_crtc_for_pipe(dev, PIPE_B));
> +		other_crtc_state =
> +			intel_atomic_get_crtc_state(state, other_crtc);
> +		if (IS_ERR(other_crtc_state))
> +			return PTR_ERR(other_crtc_state);
> +
> +		if (pipe_required_fdi_lanes(other_crtc_state) > 2) {
>  			DRM_DEBUG_KMS("fdi link B uses too many lanes to enable link C\n");
> -			return false;
> +			return -EINVAL;
>  		}
> -		return true;
> +		return 0;
>  	default:
>  		BUG();
>  	}
> @@ -5737,8 +5752,8 @@ static int ironlake_fdi_compute_config(struct intel_crtc *intel_crtc,
>  {
>  	struct drm_device *dev = intel_crtc->base.dev;
>  	struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
> -	int lane, link_bw, fdi_dotclock;
> -	bool setup_ok, needs_recompute = false;
> +	int lane, link_bw, fdi_dotclock, ret;
> +	bool needs_recompute = false;
>  
>  retry:
>  	/* FDI is a binary signal running at ~2.7GHz, encoding
> @@ -5760,9 +5775,9 @@ retry:
>  	intel_link_compute_m_n(pipe_config->pipe_bpp, lane, fdi_dotclock,
>  			       link_bw, &pipe_config->fdi_m_n);
>  
> -	setup_ok = ironlake_check_fdi_lanes(intel_crtc->base.dev,
> -					    intel_crtc->pipe, pipe_config);
> -	if (!setup_ok && pipe_config->pipe_bpp > 6*3) {
> +	ret = ironlake_check_fdi_lanes(intel_crtc->base.dev,
> +				       intel_crtc->pipe, pipe_config);
> +	if (ret == -EINVAL && pipe_config->pipe_bpp > 6*3) {
>  		pipe_config->pipe_bpp -= 2*3;
>  		DRM_DEBUG_KMS("fdi link bw constraint, reducing pipe bpp to %i\n",
>  			      pipe_config->pipe_bpp);
> @@ -5775,7 +5790,7 @@ retry:
>  	if (needs_recompute)
>  		return RETRY;
>  
> -	return setup_ok ? 0 : -EINVAL;
> +	return ret;
>  }
>  
>  static void hsw_compute_ips_config(struct intel_crtc *crtc,
> -- 
> 2.1.0
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch