Re: [PATCH v2 06/10] drm/i915: Pass encoder type to cnl_ddi_vswing_sequence() explicitly

[Manasi Navare <manasi.d.navare@intel.com>]

On Mon, Oct 16, 2017 at 05:57:01PM +0300, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> encoder->type is unreliable for DP/HDMI, so pass it in explicity into
> cnl_ddi_vswing_sequence(). This matches what we do for BXT.
>

I still dont get why we cant use encoder->type reliably?
Since if I trace back on the caller of intel_ddi_pre_enable_hdmi or
intel_ddi_pre_enable_dp, the caler intel_ddi_pre_enable() calls
either of these based on encoder->type itself.
So why do we explicitly need to pass encoder->type instead
of deriving it from encoder inside the vswing_sequenc_ functions?

May be I am missing something?

Manasi
 
> v2: Pass intel_encoder down to cnl_ddi_vswing_program(), and
>     clean up the argument types while at it
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_ddi.c | 53 +++++++++++++++++++---------------------
>  1 file changed, 25 insertions(+), 28 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> index 2d886148a653..cab72177299c 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -1920,20 +1920,21 @@ u8 intel_ddi_dp_voltage_max(struct intel_encoder *encoder)
>  		DP_TRAIN_VOLTAGE_SWING_MASK;
>  }
>  
> -static void cnl_ddi_vswing_program(struct drm_i915_private *dev_priv,
> -				    u32 level, enum port port, int type)
> +static void cnl_ddi_vswing_program(struct intel_encoder *encoder,
> +				   int level, enum intel_output_type type)
>  {
> -	const struct cnl_ddi_buf_trans *ddi_translations = NULL;
> -	u32 n_entries, val;
> -	int ln;
> +	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> +	enum port port = intel_ddi_get_encoder_port(encoder);
> +	const struct cnl_ddi_buf_trans *ddi_translations;
> +	int n_entries, ln;
> +	u32 val;
>  
> -	if (type == INTEL_OUTPUT_HDMI) {
> +	if (type == INTEL_OUTPUT_HDMI)
>  		ddi_translations = cnl_get_buf_trans_hdmi(dev_priv, &n_entries);
> -	} else if (type == INTEL_OUTPUT_DP) {
> -		ddi_translations = cnl_get_buf_trans_dp(dev_priv, &n_entries);
> -	} else if (type == INTEL_OUTPUT_EDP) {
> +	else if (type == INTEL_OUTPUT_EDP)
>  		ddi_translations = cnl_get_buf_trans_edp(dev_priv, &n_entries);
> -	}
> +	else
> +		ddi_translations = cnl_get_buf_trans_dp(dev_priv, &n_entries);
>  
>  	if (WARN_ON(ddi_translations == NULL))
>  		return;
> @@ -1986,26 +1987,22 @@ static void cnl_ddi_vswing_program(struct drm_i915_private *dev_priv,
>  	I915_WRITE(CNL_PORT_TX_DW7_GRP(port), val);
>  }
>  
> -static void cnl_ddi_vswing_sequence(struct intel_encoder *encoder, u32 level)
> +static void cnl_ddi_vswing_sequence(struct intel_encoder *encoder,
> +				    int level, enum intel_output_type type)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> -	struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
>  	enum port port = intel_ddi_get_encoder_port(encoder);
> -	int type = encoder->type;
> -	int width = 0;
> -	int rate = 0;
> +	int width, rate, ln;
>  	u32 val;
> -	int ln = 0;
>  
> -	if ((intel_dp) && (type == INTEL_OUTPUT_EDP || type == INTEL_OUTPUT_DP)) {
> +	if (type == INTEL_OUTPUT_HDMI) {
> +		width = 4;
> +		rate = 0; /* Rate is always < than 6GHz for HDMI */
> +	} else {
> +		struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
> +
>  		width = intel_dp->lane_count;
>  		rate = intel_dp->link_rate;
> -	} else if (type == INTEL_OUTPUT_HDMI) {
> -		width = 4;
> -		/* Rate is always < than 6GHz for HDMI */
> -	} else {
> -		MISSING_CASE(type);
> -		return;
>  	}
>  
>  	/*
> @@ -2014,7 +2011,7 @@ static void cnl_ddi_vswing_sequence(struct intel_encoder *encoder, u32 level)
>  	 * else clear to 0b.
>  	 */
>  	val = I915_READ(CNL_PORT_PCS_DW1_LN0(port));
> -	if (type == INTEL_OUTPUT_EDP || type == INTEL_OUTPUT_DP)
> +	if (type != INTEL_OUTPUT_HDMI)
>  		val |= COMMON_KEEPER_EN;
>  	else
>  		val &= ~COMMON_KEEPER_EN;
> @@ -2049,7 +2046,7 @@ static void cnl_ddi_vswing_sequence(struct intel_encoder *encoder, u32 level)
>  	I915_WRITE(CNL_PORT_TX_DW5_GRP(port), val);
>  
>  	/* 5. Program swing and de-emphasis */
> -	cnl_ddi_vswing_program(dev_priv, level, port, type);
> +	cnl_ddi_vswing_program(encoder, level, type);
>  
>  	/* 6. Set training enable to trigger update */
>  	val = I915_READ(CNL_PORT_TX_DW5_LN0(port));
> @@ -2089,7 +2086,7 @@ u32 bxt_signal_levels(struct intel_dp *intel_dp)
>  	u32 level = intel_ddi_dp_level(intel_dp);
>  
>  	if (IS_CANNONLAKE(dev_priv))
> -		cnl_ddi_vswing_sequence(encoder, level);
> +		cnl_ddi_vswing_sequence(encoder, level, encoder->type);
>  	else
>  		bxt_ddi_vswing_sequence(encoder, level, encoder->type);
>  
> @@ -2188,7 +2185,7 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
>  	intel_display_power_get(dev_priv, dig_port->ddi_io_power_domain);
>  
>  	if (IS_CANNONLAKE(dev_priv))
> -		cnl_ddi_vswing_sequence(encoder, level);
> +		cnl_ddi_vswing_sequence(encoder, level, encoder->type);
>  	else if (IS_GEN9_LP(dev_priv))
>  		bxt_ddi_vswing_sequence(encoder, level, encoder->type);
>  	else
> @@ -2219,7 +2216,7 @@ static void intel_ddi_pre_enable_hdmi(struct intel_encoder *encoder,
>  	intel_display_power_get(dev_priv, dig_port->ddi_io_power_domain);
>  
>  	if (IS_CANNONLAKE(dev_priv))
> -		cnl_ddi_vswing_sequence(encoder, level);
> +		cnl_ddi_vswing_sequence(encoder, level, INTEL_OUTPUT_HDMI);
>  	else if (IS_GEN9_LP(dev_priv))
>  		bxt_ddi_vswing_sequence(encoder, level, INTEL_OUTPUT_HDMI);
>  	else
> -- 
> 2.13.6
> 
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