[Intel-gfx] [RFC] drm/i915/dp: move link rate arrays where they're used

[Manasi Navare]

On Tue, Feb 27, 2018 at 12:59:11PM +0200, Jani Nikula wrote:
> Localize link rate arrays by moving them to the functions where they're
> used. Further clarify the distinction between source and sink
> capabilities. Split pre and post Haswell arrays, and get rid of the
> array size arithmetics. Use a direct rate value in the paranoia case of
> no common rates find.
> 
> Cc: Manasi Navare <manasi.d.navare at intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_dp.c | 44 +++++++++++++++++++++++++----------------
>  1 file changed, 27 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 801a21b16004..6fa6583b16bd 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -96,15 +96,6 @@ static const struct dp_link_dpll chv_dpll[] = {
>  		{ .p1 = 2, .p2 = 1, .n = 1, .m1 = 2, .m2 = 0x6c00000 } }
>  };
>  
> -static const int bxt_rates[] = { 162000, 216000, 243000, 270000,
> -				  324000, 432000, 540000 };
> -static const int skl_rates[] = { 162000, 216000, 270000,
> -				  324000, 432000, 540000 };
> -static const int cnl_rates[] = { 162000, 216000, 270000,
> -				 324000, 432000, 540000,
> -				 648000, 810000 };
> -static const int default_rates[] = { 162000, 270000, 540000 };
> -
>  /**
>   * intel_dp_is_edp - is the given port attached to an eDP panel (either CPU or PCH)
>   * @intel_dp: DP struct
> @@ -144,14 +135,17 @@ static void intel_dp_unset_edid(struct intel_dp *intel_dp);
>  /* update sink rates from dpcd */
>  static void intel_dp_set_sink_rates(struct intel_dp *intel_dp)
>  {
> +	static const int dp_rates[] = {
> +		162000, 270000, 540000
> +	};

Now that the sink rates can be as high as 810000, shouldnt dp_rates[] include that rate?
Since we use this to populate sink_rates, if the max rate from dpcd is 810000, currently
the sink rates will not get populated with that.

Manasi

>  	int i, max_rate;
>  
>  	max_rate = drm_dp_bw_code_to_link_rate(intel_dp->dpcd[DP_MAX_LINK_RATE]);
>  
> -	for (i = 0; i < ARRAY_SIZE(default_rates); i++) {
> -		if (default_rates[i] > max_rate)
> +	for (i = 0; i < ARRAY_SIZE(dp_rates); i++) {
> +		if (dp_rates[i] > max_rate)
>  			break;
> -		intel_dp->sink_rates[i] = default_rates[i];
> +		intel_dp->sink_rates[i] = dp_rates[i];
>  	}
>  
>  	intel_dp->num_sink_rates = i;
> @@ -268,6 +262,22 @@ static int cnl_max_source_rate(struct intel_dp *intel_dp)
>  static void
>  intel_dp_set_source_rates(struct intel_dp *intel_dp)
>  {
> +	/* The values must be in increasing order */
> +	static const int cnl_rates[] = {
> +		162000, 216000, 270000, 324000, 432000, 540000, 648000, 810000
> +	};
> +	static const int bxt_rates[] = {
> +		162000, 216000, 243000, 270000, 324000, 432000, 540000
> +	};
> +	static const int skl_rates[] = {
> +		162000, 216000, 270000, 324000, 432000, 540000
> +	};
> +	static const int hsw_rates[] = {
> +		162000, 270000, 540000
> +	};
> +	static const int g4x_rates[] = {
> +		162000, 270000
> +	};
>  	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
>  	struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
>  	const struct ddi_vbt_port_info *info =
> @@ -290,11 +300,11 @@ intel_dp_set_source_rates(struct intel_dp *intel_dp)
>  		size = ARRAY_SIZE(skl_rates);
>  	} else if ((IS_HASWELL(dev_priv) && !IS_HSW_ULX(dev_priv)) ||
>  		   IS_BROADWELL(dev_priv)) {
> -		source_rates = default_rates;
> -		size = ARRAY_SIZE(default_rates);
> +		source_rates = hsw_rates;
> +		size = ARRAY_SIZE(hsw_rates);
>  	} else {
> -		source_rates = default_rates;
> -		size = ARRAY_SIZE(default_rates) - 1;
> +		source_rates = g4x_rates;
> +		size = ARRAY_SIZE(g4x_rates);
>  	}
>  
>  	if (max_rate && vbt_max_rate)
> @@ -356,7 +366,7 @@ static void intel_dp_set_common_rates(struct intel_dp *intel_dp)
>  
>  	/* Paranoia, there should always be something in common. */
>  	if (WARN_ON(intel_dp->num_common_rates == 0)) {
> -		intel_dp->common_rates[0] = default_rates[0];
> +		intel_dp->common_rates[0] = 162000;
>  		intel_dp->num_common_rates = 1;
>  	}
>  }
> -- 
> 2.11.0
>