[Intel-gfx] [PATCH] drm/i915/cnl: Respect VBT max dp rate.

[Rodrigo Vivi]

Since commit 'c4fb60b9aba9 ("drm/i915/bios: add DP max link
rate to VBT child device struct")' we have the new entry
defined for max dp rate that is in use for CNL.

Let's start using it for all VBT 216+ and
also organize the cnl adjusted rates in terms of rate
and not array size.

Cc: Jani Nikula <jani.nikula at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h   |  1 +
 drivers/gpu/drm/i915/intel_bios.c |  3 +++
 drivers/gpu/drm/i915/intel_dp.c   | 37 +++++++++++++++++++++++++++++--------
 3 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index c676269ed843..66dea5c9b10e 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1282,6 +1282,7 @@ struct ddi_vbt_port_info {
 
 	uint8_t dp_boost_level;
 	uint8_t hdmi_boost_level;
+	uint8_t dp_max_link_rate;
 };
 
 enum psr_lines_to_wait {
diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index cf3f8f1ba6f7..c885daf4cc8d 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -1230,6 +1230,9 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
 		info->alternate_aux_channel = aux_channel;
 
 		sanitize_aux_ch(dev_priv, port);
+
+		if (bdb_version >= 216 && child->dp_max_link_rate)
+			info->dp_max_link_rate = child->dp_max_link_rate;
 	}
 
 	if (bdb_version >= 158) {
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 03d86ff9b805..1e34d7954355 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -220,7 +220,7 @@ intel_dp_downstream_max_dotclock(struct intel_dp *intel_dp)
 	return max_dotclk;
 }
 
-static int cnl_adjusted_max_rate(struct intel_dp *intel_dp, int size)
+static int cnl_adjusted_max_rate(struct intel_dp *intel_dp)
 {
 	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);
@@ -230,17 +230,33 @@ static int cnl_adjusted_max_rate(struct intel_dp *intel_dp, int size)
 
 	/* Low voltage SKUs are limited to max of 5.4G */
 	if (voltage == VOLTAGE_INFO_0_85V)
-		return size - 2;
+		return 540000;
 
 	/* For this SKU 8.1G is supported in all ports */
 	if (IS_CNL_WITH_PORT_F(dev_priv))
-		return size;
+		return 810000;
 
 	/* For other SKUs, max rate on ports A and B is 5.4G */
 	if (port == PORT_A || port == PORT_D)
-		return size - 2;
+		return 540000;
 
-	return size;
+	return 810000;
+}
+
+static int intel_dp_adjusted_max_rate(struct intel_dp *intel_dp)
+{
+	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 =
+		&dev_priv->vbt.ddi_port_info[dig_port->base.port];
+
+	if (info->dp_max_link_rate)
+		return info->dp_max_link_rate;
+
+	if (IS_CANNONLAKE(dev_priv))
+		return cnl_adjusted_max_rate(intel_dp);
+
+	return INT_MAX; /* No adjusted limit */
 }
 
 static void
@@ -249,7 +265,8 @@ intel_dp_set_source_rates(struct intel_dp *intel_dp)
 	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 int *source_rates;
-	int size;
+	int i, size;
+	int max_rate = intel_dp_adjusted_max_rate(intel_dp);
 
 	/* This should only be done once */
 	WARN_ON(intel_dp->source_rates || intel_dp->num_source_rates);
@@ -259,7 +276,7 @@ intel_dp_set_source_rates(struct intel_dp *intel_dp)
 		size = ARRAY_SIZE(bxt_rates);
 	} else if (IS_CANNONLAKE(dev_priv)) {
 		source_rates = cnl_rates;
-		size = cnl_adjusted_max_rate(intel_dp, ARRAY_SIZE(cnl_rates));
+		size = ARRAY_SIZE(cnl_rates);
 	} else if (IS_GEN9_BC(dev_priv)) {
 		source_rates = skl_rates;
 		size = ARRAY_SIZE(skl_rates);
@@ -272,8 +289,12 @@ intel_dp_set_source_rates(struct intel_dp *intel_dp)
 		size = ARRAY_SIZE(default_rates) - 1;
 	}
 
+	for (i = 0; i < size; i++)
+		if (source_rates[i] > max_rate)
+			break;
+
+	intel_dp->num_source_rates = i;
 	intel_dp->source_rates = source_rates;
-	intel_dp->num_source_rates = size;
 }
 
 static int intersect_rates(const int *source_rates, int source_len,
-- 
2.13.6