[PATCH RFC 8/8] drm/i915: Add support for DP link training compliance
Manasi Navare
manasi.d.navare at intel.com
Wed Oct 19 21:46:24 UTC 2016
This patch adds support to handle automated DP compliance
link training test requests. This patch has been tested with
Unigraf DPR-120 DP Compliance device for testing Link
Training Compliance.
After we get a short pulse Compliance test request, test
request values are read and hotplug uevent is sent in order
to trigger another modeset during which the pipe is configured
and link is enabled for link parameters requested by the test.
Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
Cc: Jani Nikula <jani.nikula at linux.intel.com>
Cc: Daniel Vetter <daniel.vetter at intel.com>
Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
---
drivers/gpu/drm/i915/intel_dp.c | 72 ++++++++++++++++++++++++++++++++++------
drivers/gpu/drm/i915/intel_drv.h | 2 ++
2 files changed, 63 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 78246ba..cd7a59e 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1588,6 +1588,7 @@ static int intel_dp_compute_bpp(struct intel_dp *intel_dp,
/* Conveniently, the link BW constants become indices with a shift...*/
int min_clock = 0;
int max_clock;
+ int link_rate_index;
int bpp, mode_rate;
int link_avail, link_clock;
int common_rates[DP_MAX_SUPPORTED_RATES] = {};
@@ -1636,6 +1637,19 @@ static int intel_dp_compute_bpp(struct intel_dp *intel_dp,
intel_dp->link_train_failed_link_rate = 0;
intel_dp->link_rate_index = -1;
}
+ /* Use values requested by Compliance Test Request */
+ if (intel_dp->compliance_test_link_rate &&
+ intel_dp->compliance_test_lane_count) {
+ link_rate_index = intel_dp_link_rate_index(intel_dp,
+ common_rates,
+ drm_dp_bw_code_to_link_rate(intel_dp->compliance_test_link_rate));
+ if (link_rate_index >= 0)
+ min_clock = max_clock = link_rate_index;
+ min_lane_count = max_lane_count = intel_dp->compliance_test_lane_count;
+
+ intel_dp->compliance_test_link_rate = 0;
+ intel_dp->compliance_test_lane_count = 0;
+ }
DRM_DEBUG_KMS("DP link computation with max lane count %i "
"max bw %d pixel clock %iKHz\n",
@@ -1684,6 +1698,7 @@ static int intel_dp_compute_bpp(struct intel_dp *intel_dp,
}
}
}
+
}
return false;
@@ -3865,6 +3880,29 @@ int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc)
static uint8_t intel_dp_autotest_link_training(struct intel_dp *intel_dp)
{
uint8_t test_result = DP_TEST_ACK;
+ int status = 0;
+ /* (DP CTS 1.2)
+ * 4.3.1.11
+ */
+ /* Read the TEST_LANE_COUNT and TEST_LINK_RTAE fields (DP CTS 3.1.4) */
+ status = drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_LANE_COUNT,
+ &intel_dp->compliance_test_lane_count);
+
+ if (status <= 0) {
+ DRM_DEBUG_KMS("Could not read test lane count from "
+ "reference sink\n");
+ return 0;
+ }
+ intel_dp->compliance_test_lane_count &= DP_MAX_LANE_COUNT_MASK;
+
+ status = drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_LINK_RATE,
+ &intel_dp->compliance_test_link_rate);
+ if (status <= 0) {
+ DRM_DEBUG_KMS("Could not read test link rate from "
+ "refernce sink\n");
+ return 0;
+ }
+
return test_result;
}
@@ -3965,11 +4003,14 @@ static void intel_dp_handle_test_request(struct intel_dp *intel_dp)
}
update_status:
- status = drm_dp_dpcd_write(&intel_dp->aux,
- DP_TEST_RESPONSE,
- &response, 1);
- if (status <= 0)
- DRM_DEBUG_KMS("Could not write test response to sink\n");
+ if (intel_dp->compliance_test_type == DP_TEST_LINK_TRAINING) {
+ status = drm_dp_dpcd_write(&intel_dp->aux,
+ DP_TEST_RESPONSE,
+ &response, 1);
+ if (status <= 0)
+ DRM_DEBUG_KMS("Could not write test response "
+ "to sink\n");
+ }
}
static int
@@ -4074,9 +4115,7 @@ static void intel_dp_handle_test_request(struct intel_dp *intel_dp)
if (!to_intel_crtc(intel_encoder->base.crtc)->active)
return;
- /* if link training is requested we should perform it always */
- if ((intel_dp->compliance_test_type == DP_TEST_LINK_TRAINING) ||
- (!drm_dp_channel_eq_ok(link_status, intel_dp->lane_count))) {
+ if ((!drm_dp_channel_eq_ok(link_status, intel_dp->lane_count))) {
DRM_DEBUG_KMS("%s: channel EQ not ok, retraining\n",
intel_encoder->base.name);
@@ -4101,6 +4140,9 @@ static void intel_dp_handle_test_request(struct intel_dp *intel_dp)
intel_dp_short_pulse(struct intel_dp *intel_dp)
{
struct drm_device *dev = intel_dp_to_dev(intel_dp);
+ struct intel_encoder *intel_encoder = &dp_to_dig_port(intel_dp)->base;
+ struct intel_connector *intel_connector = intel_dp->attached_connector;
+ struct drm_connector *connector = &intel_connector->base;
u8 sink_irq_vector = 0;
u8 old_sink_count = intel_dp->sink_count;
bool ret;
@@ -4135,8 +4177,9 @@ static void intel_dp_handle_test_request(struct intel_dp *intel_dp)
DP_DEVICE_SERVICE_IRQ_VECTOR,
sink_irq_vector);
- if (sink_irq_vector & DP_AUTOMATED_TEST_REQUEST)
- DRM_DEBUG_DRIVER("Test request in short pulse not handled\n");
+ if (sink_irq_vector & DP_AUTOMATED_TEST_REQUEST) {
+ intel_dp_handle_test_request(intel_dp);
+ }
if (sink_irq_vector & (DP_CP_IRQ | DP_SINK_SPECIFIC_IRQ))
DRM_DEBUG_DRIVER("CP or sink specific irq unhandled\n");
}
@@ -4144,6 +4187,11 @@ static void intel_dp_handle_test_request(struct intel_dp *intel_dp)
drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
intel_dp_check_link_status(intel_dp);
drm_modeset_unlock(&dev->mode_config.connection_mutex);
+ if ((intel_dp->compliance_test_type == DP_TEST_LINK_TRAINING)) {
+ connector->link_train_retry = true;
+ /* Send a Hotplug Uevent to userspace to start modeset */
+ drm_kms_helper_hotplug_event(intel_encoder->base.dev);
+ }
return true;
}
@@ -4421,7 +4469,9 @@ static bool intel_digital_port_connected(struct drm_i915_private *dev_priv,
/* Can't disconnect eDP, but you can close the lid... */
if (is_edp(intel_dp))
status = edp_detect(intel_dp);
- else if (intel_dp->link_train_failed) {
+ else if (intel_dp->compliance_test_type == DP_TEST_LINK_TRAINING ||
+ intel_dp->link_train_failed) {
+ intel_dp->compliance_test_type = 0;
intel_dp->link_train_failed = false;
goto out;
}
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 4b4bed6..b598215 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -963,6 +963,8 @@ struct intel_dp {
unsigned long compliance_test_type;
unsigned long compliance_test_data;
bool compliance_test_active;
+ u8 compliance_test_lane_count;
+ u8 compliance_test_link_rate;
};
struct intel_lspcon {
--
1.9.1
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