According to BSpec the link training sequence on HSW port-A should be as
follows:
1. link training: clock recovery
2. link training: equalization
3. display pipe enable
4. link training: disable (set normal mode)
Contrary to this at the moment we do step 4. already after step 2. Fix
this by adding a new intel_dp_stop_link_training function, so that we'll
end up with the following functions corresponding to the above steps:
intel_dp_start_link_train -> step 1.
intel_dp_complete_link_train -> step 2.
intel_dp_stop_link_train -> step 4.
For port-A we'll call intel_dp_stop_link_train only after enabling the
pipe for everything else we'll call it right after
intel_dp_complete_link_train to preserve the current behavior.
Tested on HSW/HSW-ULT.
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
drivers/gpu/drm/i915/intel_ddi.c | 5 ++++
drivers/gpu/drm/i915/intel_dp.c | 49 ++++++++++++++++++++++++++------------
drivers/gpu/drm/i915/intel_drv.h | 1 +
3 files changed, 40 insertions(+), 15 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index eef450b..d7da1ca 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1265,6 +1265,8 @@ static void intel_ddi_pre_enable(struct intel_encoder *intel_encoder)
intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
intel_dp_start_link_train(intel_dp);
intel_dp_complete_link_train(intel_dp);
+ if (port != PORT_A)
+ intel_dp_stop_link_train(intel_dp);
}
}
@@ -1326,6 +1328,9 @@ static void intel_enable_ddi(struct intel_encoder *intel_encoder)
} else if (type == INTEL_OUTPUT_EDP) {
struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
+ if (port == PORT_A)
+ intel_dp_stop_link_train(intel_dp);
+
ironlake_edp_backlight_on(intel_dp);
}
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index dd4100f..57f4585 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1389,6 +1389,7 @@ static void intel_enable_dp(struct intel_encoder *encoder)
ironlake_edp_panel_on(intel_dp);
ironlake_edp_panel_vdd_off(intel_dp, true);
intel_dp_complete_link_train(intel_dp);
+ intel_dp_stop_link_train(intel_dp);
ironlake_edp_backlight_on(intel_dp);
if (IS_VALLEYVIEW(dev)) {
@@ -1887,10 +1888,9 @@ intel_dp_set_link_train(struct intel_dp *intel_dp,
struct drm_i915_private *dev_priv = dev->dev_private;
enum port port = intel_dig_port->port;
int ret;
- uint32_t temp;
if (HAS_DDI(dev)) {
- temp = I915_READ(DP_TP_CTL(port));
+ uint32_t temp = I915_READ(DP_TP_CTL(port));
if (dp_train_pat & DP_LINK_SCRAMBLING_DISABLE)
temp |= DP_TP_CTL_SCRAMBLE_DISABLE;
@@ -1900,18 +1900,6 @@ intel_dp_set_link_train(struct intel_dp *intel_dp,
temp &= ~DP_TP_CTL_LINK_TRAIN_MASK;
switch (dp_train_pat & DP_TRAINING_PATTERN_MASK) {
case DP_TRAINING_PATTERN_DISABLE:
-
- if (port != PORT_A) {
- temp |= DP_TP_CTL_LINK_TRAIN_IDLE;
- I915_WRITE(DP_TP_CTL(port), temp);
-
- if (wait_for((I915_READ(DP_TP_STATUS(port)) &
- DP_TP_STATUS_IDLE_DONE), 1))
- DRM_ERROR("Timed out waiting for DP idle patterns\n");
-
- temp &= ~DP_TP_CTL_LINK_TRAIN_MASK;
- }
-
temp |= DP_TP_CTL_LINK_TRAIN_NORMAL;
break;
@@ -1987,6 +1975,27 @@ intel_dp_set_link_train(struct intel_dp *intel_dp,
return true;
}
+static void intel_dp_idle_link_train(struct intel_dp *intel_dp)
+{
+ struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+ struct drm_device *dev = intel_dig_port->base.base.dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ enum port port = intel_dig_port->port;
+ uint32_t l;
+
+ if (!HAS_DDI(dev) || port == PORT_A)
+ return;
+
+ l = I915_READ(DP_TP_CTL(port));
+ l &= ~DP_TP_CTL_LINK_TRAIN_MASK;
+ l |= DP_TP_CTL_LINK_TRAIN_IDLE;
+ I915_WRITE(DP_TP_CTL(port), l);
+
+ if (wait_for((I915_READ(DP_TP_STATUS(port)) & DP_TP_STATUS_IDLE_DONE),
+ 1))
+ DRM_ERROR("Timed out waiting for DP idle patterns\n");
+}
+
/* Enable corresponding port and start training pattern 1 */
void
intel_dp_start_link_train(struct intel_dp *intel_dp)
@@ -2129,10 +2138,19 @@ intel_dp_complete_link_train(struct intel_dp *intel_dp)
++tries;
}
+ intel_dp_idle_link_train(intel_dp);
+
+ intel_dp->DP = DP;
+
if (channel_eq)
DRM_DEBUG_KMS("Channel EQ done. DP Training successfull\n");
- intel_dp_set_link_train(intel_dp, DP, DP_TRAINING_PATTERN_DISABLE);
+}
+
+void intel_dp_stop_link_train(struct intel_dp *intel_dp)
+{
+ intel_dp_set_link_train(intel_dp, intel_dp->DP,
+ DP_TRAINING_PATTERN_DISABLE);
}
static void
@@ -2340,6 +2358,7 @@ intel_dp_check_link_status(struct intel_dp *intel_dp)
drm_get_encoder_name(&intel_encoder->base));
intel_dp_start_link_train(intel_dp);
intel_dp_complete_link_train(intel_dp);
+ intel_dp_stop_link_train(intel_dp);
}
}
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 66922f8..684a90e 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -525,6 +525,7 @@ extern void intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
extern void intel_dp_init_link_config(struct intel_dp *intel_dp);
extern void intel_dp_start_link_train(struct intel_dp *intel_dp);
extern void intel_dp_complete_link_train(struct intel_dp *intel_dp);
+extern void intel_dp_stop_link_train(struct intel_dp *intel_dp);
extern void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode);
extern void intel_dp_encoder_destroy(struct drm_encoder *encoder);
extern void intel_dp_check_link_status(struct intel_dp *intel_dp);
--
1.7.10.4
