[Intel-gfx] [PATCH 5/7] drm/i915/dp: group link config limits in a struct

[Manasi Navare]

On Thu, Apr 05, 2018 at 05:39:03PM +0300, Jani Nikula wrote:
> Also use same min/max model for bpp, and adjust debug logging while at
> it.
> 

Reviewed-by: Manasi Navare <manasi.d.navare at intel.com>

> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_dp.c | 57 ++++++++++++++++++++++++-----------------
>  1 file changed, 33 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index dd42e0422af6..3c5fbdf42b9b 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -1647,6 +1647,12 @@ void intel_dp_compute_rate(struct intel_dp *intel_dp, int port_clock,
>  	}
>  }
>  
> +struct link_config_limits {
> +	int min_clock, max_clock;
> +	int min_lane_count, max_lane_count;
> +	int min_bpp, max_bpp;
> +};
> +
>  static int intel_dp_compute_bpp(struct intel_dp *intel_dp,
>  				struct intel_crtc_state *pipe_config)
>  {
> @@ -1704,21 +1710,25 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
>  {
>  	struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
>  	struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
> -	int lane_count, clock;
> -	int min_lane_count = 1;
> -	int max_lane_count = intel_dp_max_lane_count(intel_dp);
> -	int min_clock = 0;
> -	int max_clock;
> -	int bpp, mode_rate;
> -	int link_avail, link_clock;
> +	struct link_config_limits limits;
> +	int bpp, clock, lane_count;
> +	int mode_rate, link_avail, link_clock;
>  	int common_len;
> +
>  	common_len = intel_dp_common_len_rate_limit(intel_dp,
>  						    intel_dp->max_link_rate);
>  
>  	/* No common link rates between source and sink */
>  	WARN_ON(common_len <= 0);
>  
> -	max_clock = common_len - 1;
> +	limits.min_clock = 0;
> +	limits.max_clock = common_len - 1;
> +
> +	limits.min_lane_count = 1;
> +	limits.max_lane_count = intel_dp_max_lane_count(intel_dp);
> +
> +	limits.min_bpp = 6 * 3;
> +	limits.max_bpp = intel_dp_compute_bpp(intel_dp, pipe_config);
>  
>  	/* Use values requested by Compliance Test Request */
>  	if (intel_dp->compliance.test_type == DP_TEST_LINK_TRAINING) {
> @@ -1733,18 +1743,11 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
>  						    intel_dp->num_common_rates,
>  						    intel_dp->compliance.test_link_rate);
>  			if (index >= 0)
> -				min_clock = max_clock = index;
> -			min_lane_count = max_lane_count = intel_dp->compliance.test_lane_count;
> +				limits.min_clock = limits.max_clock = index;
> +			limits.min_lane_count = limits.max_lane_count = intel_dp->compliance.test_lane_count;
>  		}
>  	}
> -	DRM_DEBUG_KMS("DP link computation with max lane count %i "
> -		      "max bw %d pixel clock %iKHz\n",
> -		      max_lane_count, intel_dp->common_rates[max_clock],
> -		      adjusted_mode->crtc_clock);
>  
> -	/* Walk through all bpp values. Luckily they're all nicely spaced with 2
> -	 * bpc in between. */
> -	bpp = intel_dp_compute_bpp(intel_dp, pipe_config);
>  	if (intel_dp_is_edp(intel_dp)) {
>  		/*
>  		 * Use the maximum clock and number of lanes the eDP panel
> @@ -1753,18 +1756,24 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
>  		 * configuration, and typically these values correspond to the
>  		 * native resolution of the panel.
>  		 */
> -		min_lane_count = max_lane_count;
> -		min_clock = max_clock;
> +		limits.min_lane_count = limits.max_lane_count;
> +		limits.min_clock = limits.max_clock;
>  	}
>  
> -	for (; bpp >= 6*3; bpp -= 2*3) {
> +	DRM_DEBUG_KMS("DP link computation with max lane count %i "
> +		      "max rate %d max bpp %d pixel clock %iKHz\n",
> +		      limits.max_lane_count,
> +		      intel_dp->common_rates[limits.max_clock],
> +		      limits.max_bpp, adjusted_mode->crtc_clock);
> +
> +	for (bpp = limits.max_bpp; bpp >= limits.min_bpp; bpp -= 2 * 3) {
>  		mode_rate = intel_dp_link_required(adjusted_mode->crtc_clock,
>  						   bpp);
>  
> -		for (clock = min_clock; clock <= max_clock; clock++) {
> -			for (lane_count = min_lane_count;
> -				lane_count <= max_lane_count;
> -				lane_count <<= 1) {
> +		for (clock = limits.min_clock; clock <= limits.max_clock; clock++) {
> +			for (lane_count = limits.min_lane_count;
> +			     lane_count <= limits.max_lane_count;
> +			     lane_count <<= 1) {
>  
>  				link_clock = intel_dp->common_rates[clock];
>  				link_avail = intel_dp_max_data_rate(link_clock,
> -- 
> 2.11.0
>