Re: [PATCH 2/3] drm/i915/ehl: Remove unsupported cd clocks

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 19 Jun 2019, Ville Syrjälä <ville.syrjala@linux.intel.com> wrote:
> On Tue, Jun 18, 2019 at 03:50:34PM -0700, José Roberto de Souza wrote:
>> EHL do not support 648 and 652.8 MHz.
>
> You should modify the max_cdclk() function instead. I think that along
> should be sufficient.

Side note, these "if (foo) len--;" constructs lead to later
trouble. Either pick a different array based on the platform, or have a
way to filter the values (e.g. by max or by min).

The last "len--" I untangled was the DP link rate support.


BR,
Jani.


>
>> 
>> BSpec: 20598
>> Cc: Clint Taylor <Clinton.A.Taylor@intel.com>
>> Cc: Matt Roper <matthew.d.roper@intel.com>
>> Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
>> ---
>>  drivers/gpu/drm/i915/display/intel_cdclk.c | 17 +++++++++++++----
>>  1 file changed, 13 insertions(+), 4 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
>> index d560e25d3fb5..26c17ecf2083 100644
>> --- a/drivers/gpu/drm/i915/display/intel_cdclk.c
>> +++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
>> @@ -1754,7 +1754,8 @@ static void cnl_sanitize_cdclk(struct drm_i915_private *dev_priv)
>>  	dev_priv->cdclk.hw.vco = -1;
>>  }
>>  
>> -static int icl_calc_cdclk(int min_cdclk, unsigned int ref)
>> +static int icl_calc_cdclk(struct drm_i915_private *dev_priv, int min_cdclk,
>> +			  unsigned int ref)
>>  {
>>  	const int ranges_24[] = { 180000, 192000, 312000, 552000, 648000 };
>>  	const int ranges_19_38[] = { 172800, 192000, 307200, 556800, 652800 };
>> @@ -1776,6 +1777,12 @@ static int icl_calc_cdclk(int min_cdclk, unsigned int ref)
>>  		break;
>>  	}
>>  
>> +	/*
>> +	 * EHL do not support 648 and 652.8 MHz, so just decrement the len
>> +	 */
>> +	if (IS_ELKHARTLAKE(dev_priv))
>> +		len--;
>> +
>>  	for (i = 0; i < len; i++) {
>>  		if (min_cdclk <= ranges[i])
>>  			return ranges[i];
>> @@ -1954,7 +1961,8 @@ static void icl_init_cdclk(struct drm_i915_private *dev_priv)
>>  	DRM_DEBUG_KMS("Sanitizing cdclk programmed by pre-os\n");
>>  
>>  	sanitized_state.ref = dev_priv->cdclk.hw.ref;
>> -	sanitized_state.cdclk = icl_calc_cdclk(0, sanitized_state.ref);
>> +	sanitized_state.cdclk = icl_calc_cdclk(dev_priv, 0,
>> +					       sanitized_state.ref);
>>  	sanitized_state.vco = icl_calc_cdclk_pll_vco(dev_priv,
>>  						     sanitized_state.cdclk);
>>  	sanitized_state.voltage_level =
>> @@ -2554,7 +2562,7 @@ static int icl_modeset_calc_cdclk(struct intel_atomic_state *state)
>>  	if (min_cdclk < 0)
>>  		return min_cdclk;
>>  
>> -	cdclk = icl_calc_cdclk(min_cdclk, ref);
>> +	cdclk = icl_calc_cdclk(dev_priv, min_cdclk, ref);
>>  	vco = icl_calc_cdclk_pll_vco(dev_priv, cdclk);
>>  
>>  	state->cdclk.logical.vco = vco;
>> @@ -2564,7 +2572,8 @@ static int icl_modeset_calc_cdclk(struct intel_atomic_state *state)
>>  		    cnl_compute_min_voltage_level(state));
>>  
>>  	if (!state->active_crtcs) {
>> -		cdclk = icl_calc_cdclk(state->cdclk.force_min_cdclk, ref);
>> +		cdclk = icl_calc_cdclk(dev_priv, state->cdclk.force_min_cdclk,
>> +				       ref);
>>  		vco = icl_calc_cdclk_pll_vco(dev_priv, cdclk);
>>  
>>  		state->cdclk.actual.vco = vco;
>> -- 
>> 2.22.0
>> 
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-- 
Jani Nikula, Intel Open Source Graphics Center
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