Re: [PATCH 7/8] drm/i915: Move max voltage and pre emphasis to intel_dp_link_training.c

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As an FYI, both of these functions need to be rewritten when we want the code to be 
compliant to DP spec.
We should read the pre-emphasis given by the panel and if vwing exeeds max value we should use the max vswing supported for that pre-emphasis but current code is opposite of that. you can read more detailed logic in section "3.5.1.2 Link Training" 
in DP Spec.
by the way same is true for much of the link training logic and related functions i don't know if such rewriting should be done after fixing those or before :(. 

regards,
Sivakumar.

On 9/8/2015 6:31 PM, Ville Syrjälä wrote:

On Tue, Sep 08, 2015 at 03:27:58PM +0300, Ander Conselvan de Oliveira wrote:

So link training tests can use real hardware limits.

These need to be kept in sync with the _signal_levels() functions, so
moving them to a separate file is a bit questionable.

I suggest that we should attempt to restructure this information as
some kind of tables, from which we can look up the max values as
well as the hardware specific values for each setting.

That of course won't solve your problem. So far I don't know what your
test even does and why does it need this information, so I guess I'll
need to read on...


---
  drivers/gpu/drm/i915/intel_dp.c               | 99 ---------------------------
  drivers/gpu/drm/i915/intel_dp_link_training.c | 92 +++++++++++++++++++++++++
  drivers/gpu/drm/i915/intel_drv.h              | 11 +--
  3 files changed, 99 insertions(+), 103 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 5778059..da87aef 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -111,13 +111,6 @@ static bool is_edp(struct intel_dp *intel_dp)
  	return intel_dig_port->base.type == INTEL_OUTPUT_EDP;
  }
-static struct drm_device *intel_dp_to_dev(struct intel_dp *intel_dp) 
-{
-	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
-
-	return intel_dig_port->base.base.dev;
-}
-
  static struct intel_dp *intel_attached_dp(struct drm_connector *connector)
  {
  	return enc_to_intel_dp(&intel_attached_encoder(connector)->base);
@@ -3054,98 +3047,6 @@ intel_dp_get_link_status(struct intel_dp *intel_dp, uint8_t link_status[DP_LINK_
  				       DP_LINK_STATUS_SIZE) == DP_LINK_STATUS_SIZE;
  }
-/* These are source-specific values. */ 
-uint8_t
-intel_dp_voltage_max(struct intel_dp *intel_dp)
-{
-	struct drm_device *dev = intel_dp_to_dev(intel_dp);
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	enum port port = dp_to_dig_port(intel_dp)->port;
-
-	if (IS_BROXTON(dev))
-		return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
-	else if (INTEL_INFO(dev)->gen >= 9) {
-		if (dev_priv->edp_low_vswing && port == PORT_A)
-			return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
-		return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
-	} else if (IS_VALLEYVIEW(dev))
-		return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
-	else if (IS_GEN7(dev) && port == PORT_A)
-		return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
-	else if (HAS_PCH_CPT(dev) && port != PORT_A)
-		return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
-	else
-		return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
-}
-
-uint8_t
-intel_dp_pre_emphasis_max(struct intel_dp *intel_dp, uint8_t voltage_swing)
-{
-	struct drm_device *dev = intel_dp_to_dev(intel_dp);
-	enum port port = dp_to_dig_port(intel_dp)->port;
-
-	if (INTEL_INFO(dev)->gen >= 9) {
-		switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
-			return DP_TRAIN_PRE_EMPH_LEVEL_3;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
-			return DP_TRAIN_PRE_EMPH_LEVEL_2;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
-			return DP_TRAIN_PRE_EMPH_LEVEL_1;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
-			return DP_TRAIN_PRE_EMPH_LEVEL_0;
-		default:
-			return DP_TRAIN_PRE_EMPH_LEVEL_0;
-		}
-	} else if (IS_HASWELL(dev) || IS_BROADWELL(dev)) {
-		switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
-			return DP_TRAIN_PRE_EMPH_LEVEL_3;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
-			return DP_TRAIN_PRE_EMPH_LEVEL_2;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
-			return DP_TRAIN_PRE_EMPH_LEVEL_1;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
-		default:
-			return DP_TRAIN_PRE_EMPH_LEVEL_0;
-		}
-	} else if (IS_VALLEYVIEW(dev)) {
-		switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
-			return DP_TRAIN_PRE_EMPH_LEVEL_3;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
-			return DP_TRAIN_PRE_EMPH_LEVEL_2;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
-			return DP_TRAIN_PRE_EMPH_LEVEL_1;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
-		default:
-			return DP_TRAIN_PRE_EMPH_LEVEL_0;
-		}
-	} else if (IS_GEN7(dev) && port == PORT_A) {
-		switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
-			return DP_TRAIN_PRE_EMPH_LEVEL_2;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
-			return DP_TRAIN_PRE_EMPH_LEVEL_1;
-		default:
-			return DP_TRAIN_PRE_EMPH_LEVEL_0;
-		}
-	} else {
-		switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
-			return DP_TRAIN_PRE_EMPH_LEVEL_2;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
-			return DP_TRAIN_PRE_EMPH_LEVEL_2;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
-			return DP_TRAIN_PRE_EMPH_LEVEL_1;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
-		default:
-			return DP_TRAIN_PRE_EMPH_LEVEL_0;
-		}
-	}
-}
-
  static uint32_t vlv_signal_levels(struct intel_dp *intel_dp)
  {
  	struct drm_device *dev = intel_dp_to_dev(intel_dp);
diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c
index f33cbbb..8d27dce 100644
--- a/drivers/gpu/drm/i915/intel_dp_link_training.c
+++ b/drivers/gpu/drm/i915/intel_dp_link_training.c
@@ -23,6 +23,98 @@
#include "intel_drv.h" +/* These are source-specific values. */ 
+static uint8_t
+intel_dp_voltage_max(struct intel_dp *intel_dp)
+{
+	struct drm_device *dev = intel_dp_to_dev(intel_dp);
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	enum port port = dp_to_dig_port(intel_dp)->port;
+
+	if (IS_BROXTON(dev))
+		return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
+	else if (INTEL_INFO(dev)->gen >= 9) {
+		if (dev_priv->edp_low_vswing && port == PORT_A)
+			return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
+		return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
+	} else if (IS_VALLEYVIEW(dev))
+		return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
+	else if (IS_GEN7(dev) && port == PORT_A)
+		return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
+	else if (HAS_PCH_CPT(dev) && port != PORT_A)
+		return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
+	else
+		return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
+}
+
+static uint8_t
+intel_dp_pre_emphasis_max(struct intel_dp *intel_dp, uint8_t voltage_swing)
+{
+	struct drm_device *dev = intel_dp_to_dev(intel_dp);
+	enum port port = dp_to_dig_port(intel_dp)->port;
+
+	if (INTEL_INFO(dev)->gen >= 9) {
+		switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
+			return DP_TRAIN_PRE_EMPH_LEVEL_3;
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
+			return DP_TRAIN_PRE_EMPH_LEVEL_2;
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
+			return DP_TRAIN_PRE_EMPH_LEVEL_1;
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
+			return DP_TRAIN_PRE_EMPH_LEVEL_0;
+		default:
+			return DP_TRAIN_PRE_EMPH_LEVEL_0;
+		}
+	} else if (IS_HASWELL(dev) || IS_BROADWELL(dev)) {
+		switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
+			return DP_TRAIN_PRE_EMPH_LEVEL_3;
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
+			return DP_TRAIN_PRE_EMPH_LEVEL_2;
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
+			return DP_TRAIN_PRE_EMPH_LEVEL_1;
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
+		default:
+			return DP_TRAIN_PRE_EMPH_LEVEL_0;
+		}
+	} else if (IS_VALLEYVIEW(dev)) {
+		switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
+			return DP_TRAIN_PRE_EMPH_LEVEL_3;
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
+			return DP_TRAIN_PRE_EMPH_LEVEL_2;
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
+			return DP_TRAIN_PRE_EMPH_LEVEL_1;
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
+		default:
+			return DP_TRAIN_PRE_EMPH_LEVEL_0;
+		}
+	} else if (IS_GEN7(dev) && port == PORT_A) {
+		switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
+			return DP_TRAIN_PRE_EMPH_LEVEL_2;
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
+			return DP_TRAIN_PRE_EMPH_LEVEL_1;
+		default:
+			return DP_TRAIN_PRE_EMPH_LEVEL_0;
+		}
+	} else {
+		switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
+			return DP_TRAIN_PRE_EMPH_LEVEL_2;
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
+			return DP_TRAIN_PRE_EMPH_LEVEL_2;
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
+			return DP_TRAIN_PRE_EMPH_LEVEL_1;
+		case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
+		default:
+			return DP_TRAIN_PRE_EMPH_LEVEL_0;
+		}
+	}
+}
+
  static void
  intel_get_adjust_train(struct intel_dp *intel_dp,
  		       const uint8_t link_status[DP_LINK_STATUS_SIZE])
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 29ae4bb..671a20f 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1216,15 +1216,18 @@ intel_dp_program_link_training_pattern(struct intel_dp *intel_dp,
  void
  intel_dp_update_signal_levels(struct intel_dp *intel_dp);
  void intel_dp_set_idle_link_train(struct intel_dp *intel_dp);
-uint8_t
-intel_dp_voltage_max(struct intel_dp *intel_dp);
-uint8_t
-intel_dp_pre_emphasis_max(struct intel_dp *intel_dp, uint8_t voltage_swing);
  void intel_dp_compute_rate(struct intel_dp *intel_dp, int port_clock,
  			   uint8_t *link_bw, uint8_t *rate_select);
  bool intel_dp_source_supports_hbr2(struct drm_device *dev);
  bool
  intel_dp_get_link_status(struct intel_dp *intel_dp, uint8_t link_status[DP_LINK_STATUS_SIZE]);
+static inline struct drm_device *intel_dp_to_dev(struct intel_dp *intel_dp)
+{
+	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+
+	return intel_dig_port->base.base.dev;
+}
+
/* intel_dp_mst.c */ 
  int intel_dp_mst_encoder_init(struct intel_digital_port *intel_dig_port, int conn_id);
--
2.4.3


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