Add connector debugfs entries to set a target link rate/lane count to be
used by a link training afterwards. After setting a target link
rate/lane count reset the link training parameters and for a non-auto
target disable reducing the link parameters via the fallback logic. The
former one can be used after testing link training failure scenarios
- via debugfs entries added later - to reset the reduced link parameters
after the test.
Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
---
.../drm/i915/display/intel_display_debugfs.c | 218 ++++++++++++++++++
.../drm/i915/display/intel_display_types.h | 2 +
drivers/gpu/drm/i915/display/intel_dp.c | 63 ++++-
drivers/gpu/drm/i915/display/intel_dp.h | 2 +
.../drm/i915/display/intel_dp_link_training.c | 6 +
5 files changed, 282 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
index 35f9f86ef70f4..521721a20358f 100644
--- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
+++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
@@ -1316,6 +1316,215 @@ static const struct file_operations i915_dsc_bpc_fops = {
.write = i915_dsc_bpc_write
};
+static struct intel_dp *intel_connector_to_intel_dp(struct intel_connector *connector)
+{
+ if (connector->mst_port)
+ return connector->mst_port;
+ else
+ return enc_to_intel_dp(intel_attached_encoder(connector));
+}
+
+static int i915_dp_requested_link_rate_show(struct seq_file *m, void *data)
+{
+ struct intel_connector *connector = to_intel_connector(m->private);
+ struct drm_i915_private *i915 = to_i915(connector->base.dev);
+ struct intel_dp *intel_dp;
+ int ret;
+ int i;
+
+ ret = drm_modeset_lock_single_interruptible(&i915->drm.mode_config.connection_mutex);
+ if (ret)
+ return ret;
+
+ intel_dp = intel_connector_to_intel_dp(connector);
+
+ seq_printf(m, "%sauto%s",
+ intel_dp->requested_link_rate == 0 ? "[" : "",
+ intel_dp->requested_link_rate == 0 ? "]" : "");
+
+ for (i = 0; i < intel_dp->num_source_rates; i++)
+ seq_printf(m, " %s%d%s%s",
+ intel_dp->source_rates[i] == intel_dp->requested_link_rate ? "[" : "",
+ intel_dp->source_rates[i],
+ intel_dp->link_trained &&
+ intel_dp->source_rates[i] == intel_dp->link_rate ? "*" : "",
+ intel_dp->source_rates[i] == intel_dp->requested_link_rate ? "]" : "");
+
+ drm_modeset_unlock(&i915->drm.mode_config.connection_mutex);
+
+ seq_putc(m, '\n');
+
+ return 0;
+}
+
+static int parse_link_rate(struct intel_dp *intel_dp, const char __user *ubuf, size_t len)
+{
+ char *kbuf;
+ const char *p;
+ int rate;
+ int ret = 0;
+
+ kbuf = memdup_user_nul(ubuf, len);
+ if (IS_ERR(kbuf))
+ return PTR_ERR(kbuf);
+
+ p = strim(kbuf);
+
+ if (!strcmp(p, "auto")) {
+ rate = 0;
+ } else {
+ ret = kstrtoint(p, 0, &rate);
+ if (ret < 0)
+ goto out_free;
+
+ if (intel_dp_rate_index(intel_dp->source_rates,
+ intel_dp->num_source_rates,
+ rate) < 0)
+ ret = -EINVAL;
+ }
+
+out_free:
+ kfree(kbuf);
+
+ return ret < 0 ? ret : rate;
+}
+
+static ssize_t i915_dp_requested_link_rate_write(struct file *file,
+ const char __user *ubuf,
+ size_t len, loff_t *offp)
+{
+ struct seq_file *m = file->private_data;
+ struct intel_connector *connector = to_intel_connector(m->private);
+ struct drm_i915_private *i915 = to_i915(connector->base.dev);
+ struct intel_dp *intel_dp = intel_connector_to_intel_dp(connector);
+ int rate;
+ int ret;
+
+ ret = drm_modeset_lock_single_interruptible(&i915->drm.mode_config.connection_mutex);
+ if (ret)
+ return ret;
+
+ intel_dp = intel_connector_to_intel_dp(connector);
+
+ rate = parse_link_rate(intel_dp, ubuf, len);
+ if (rate < 0) {
+ drm_modeset_unlock(&i915->drm.mode_config.connection_mutex);
+
+ return rate;
+ }
+
+ intel_dp_reset_link_train_params(intel_dp);
+ intel_dp->requested_link_rate = rate;
+
+ drm_modeset_unlock(&i915->drm.mode_config.connection_mutex);
+
+ *offp += len;
+
+ return len;
+}
+DEFINE_SHOW_STORE_ATTRIBUTE(i915_dp_requested_link_rate);
+
+static int i915_dp_requested_lane_count_show(struct seq_file *m, void *data)
+{
+ struct intel_connector *connector = to_intel_connector(m->private);
+ struct drm_i915_private *i915 = to_i915(connector->base.dev);
+ struct intel_dp *intel_dp;
+ int ret;
+ int i;
+
+ ret = drm_modeset_lock_single_interruptible(&i915->drm.mode_config.connection_mutex);
+ if (ret)
+ return ret;
+
+ intel_dp = intel_connector_to_intel_dp(connector);
+
+ seq_printf(m, "%sauto%s",
+ intel_dp->requested_lane_count == 0 ? "[" : "",
+ intel_dp->requested_lane_count == 0 ? "]" : "");
+
+ for (i = 1; i <= 4; i <<= 1)
+ seq_printf(m, " %s%d%s%s",
+ i == intel_dp->requested_lane_count ? "[" : "",
+ i,
+ intel_dp->link_trained &&
+ i == intel_dp->lane_count ? "*" : "",
+ i == intel_dp->requested_lane_count ? "]" : "");
+
+ drm_modeset_unlock(&i915->drm.mode_config.connection_mutex);
+
+ seq_putc(m, '\n');
+
+ return 0;
+}
+
+static int parse_lane_count(const char __user *ubuf, size_t len)
+{
+ char *kbuf;
+ const char *p;
+ int lane_count;
+ int ret = 0;
+
+ kbuf = memdup_user_nul(ubuf, len);
+ if (IS_ERR(kbuf))
+ return PTR_ERR(kbuf);
+
+ p = strim(kbuf);
+
+ if (!strcmp(p, "auto")) {
+ lane_count = 0;
+ } else {
+ ret = kstrtoint(p, 0, &lane_count);
+ if (ret < 0)
+ goto out_free;
+
+ switch (lane_count) {
+ case 1:
+ case 2:
+ case 4:
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ }
+
+out_free:
+ kfree(kbuf);
+
+ return ret < 0 ? ret : lane_count;
+}
+
+static ssize_t i915_dp_requested_lane_count_write(struct file *file,
+ const char __user *ubuf,
+ size_t len, loff_t *offp)
+{
+ struct seq_file *m = file->private_data;
+ struct intel_connector *connector = to_intel_connector(m->private);
+ struct drm_i915_private *i915 = to_i915(connector->base.dev);
+ struct intel_dp *intel_dp;
+ int lane_count;
+ int ret;
+
+ lane_count = parse_lane_count(ubuf, len);
+ if (lane_count < 0)
+ return lane_count;
+
+ ret = drm_modeset_lock_single_interruptible(&i915->drm.mode_config.connection_mutex);
+ if (ret)
+ return ret;
+
+ intel_dp = intel_connector_to_intel_dp(connector);
+
+ intel_dp_reset_link_train_params(intel_dp);
+ intel_dp->requested_lane_count = lane_count;
+
+ drm_modeset_unlock(&i915->drm.mode_config.connection_mutex);
+
+ *offp += len;
+
+ return len;
+}
+DEFINE_SHOW_STORE_ATTRIBUTE(i915_dp_requested_lane_count);
+
static int i915_dsc_output_format_show(struct seq_file *m, void *data)
{
struct intel_connector *connector = m->private;
@@ -1523,6 +1732,15 @@ void intel_connector_debugfs_add(struct intel_connector *connector)
connector, &i915_hdcp_sink_capability_fops);
}
+ if (connector_type == DRM_MODE_CONNECTOR_DisplayPort ||
+ connector_type == DRM_MODE_CONNECTOR_eDP) {
+ debugfs_create_file("i915_dp_link_rate", 0644, root,
+ connector, &i915_dp_requested_link_rate_fops);
+
+ debugfs_create_file("i915_dp_lane_count", 0644, root,
+ connector, &i915_dp_requested_lane_count_fops);
+ }
+
if (DISPLAY_VER(i915) >= 11 &&
((connector_type == DRM_MODE_CONNECTOR_DisplayPort && !connector->mst_port) ||
connector_type == DRM_MODE_CONNECTOR_eDP)) {
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index fb71bc7eb3d9a..351c445d3cb5b 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1758,6 +1758,8 @@ struct intel_dp {
/* intersection of source and sink rates */
int num_common_rates;
int common_rates[DP_MAX_SUPPORTED_RATES];
+ int requested_link_rate;
+ int requested_lane_count;
struct {
/* Max lane count for the current link */
int max_lane_count;
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 5eafda7175e2a..367970f956863 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -345,7 +345,7 @@ int intel_dp_max_common_rate(struct intel_dp *intel_dp)
return intel_dp_common_rate(intel_dp, intel_dp->num_common_rates - 1);
}
-static int intel_dp_max_source_lane_count(struct intel_digital_port *dig_port)
+int intel_dp_max_source_lane_count(struct intel_digital_port *dig_port)
{
int vbt_max_lanes = intel_bios_dp_max_lane_count(dig_port->base.devdata);
int max_lanes = dig_port->max_lanes;
@@ -371,19 +371,39 @@ int intel_dp_max_common_lane_count(struct intel_dp *intel_dp)
return min3(source_max, sink_max, lane_max);
}
+static int requested_lane_count(struct intel_dp *intel_dp)
+{
+ return clamp(intel_dp->requested_lane_count, 1, intel_dp_max_common_lane_count(intel_dp));
+}
+
int intel_dp_max_lane_count(struct intel_dp *intel_dp)
{
- switch (intel_dp->link_train.max_lane_count) {
+ int lane_count;
+
+ if (intel_dp->requested_lane_count)
+ lane_count = requested_lane_count(intel_dp);
+ else
+ lane_count = intel_dp->link_train.max_lane_count;
+
+ switch (lane_count) {
case 1:
case 2:
case 4:
- return intel_dp->link_train.max_lane_count;
+ return lane_count;
default:
- MISSING_CASE(intel_dp->link_train.max_lane_count);
+ MISSING_CASE(lane_count);
return 1;
}
}
+static int intel_dp_min_lane_count(struct intel_dp *intel_dp)
+{
+ if (intel_dp->requested_lane_count)
+ return requested_lane_count(intel_dp);
+
+ return 1;
+}
+
/*
* The required data bandwidth for a mode with given pixel clock and bpp. This
* is the required net bandwidth independent of the data bandwidth efficiency.
@@ -1306,16 +1326,38 @@ static void intel_dp_print_rates(struct intel_dp *intel_dp)
drm_dbg_kms(&i915->drm, "common rates: %s\n", str);
}
+static int requested_rate(struct intel_dp *intel_dp)
+{
+ int len = intel_dp_common_len_rate_limit(intel_dp, intel_dp->requested_link_rate);
+
+ if (len == 0)
+ return intel_dp_common_rate(intel_dp, 0);
+
+ return intel_dp_common_rate(intel_dp, len - 1);
+}
+
int
intel_dp_max_link_rate(struct intel_dp *intel_dp)
{
int len;
+ if (intel_dp->requested_link_rate)
+ return requested_rate(intel_dp);
+
len = intel_dp_common_len_rate_limit(intel_dp, intel_dp->link_train.max_rate);
return intel_dp_common_rate(intel_dp, len - 1);
}
+static int
+intel_dp_min_link_rate(struct intel_dp *intel_dp)
+{
+ if (intel_dp->requested_link_rate)
+ return requested_rate(intel_dp);
+
+ return intel_dp_common_rate(intel_dp, 0);
+}
+
int intel_dp_rate_select(struct intel_dp *intel_dp, int rate)
{
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
@@ -2285,13 +2327,14 @@ intel_dp_compute_config_limits(struct intel_dp *intel_dp,
bool dsc,
struct link_config_limits *limits)
{
- limits->min_rate = intel_dp_common_rate(intel_dp, 0);
+ limits->min_rate = intel_dp_min_link_rate(intel_dp);
limits->max_rate = intel_dp_max_link_rate(intel_dp);
/* FIXME 128b/132b SST support missing */
limits->max_rate = min(limits->max_rate, 810000);
+ limits->min_rate = min(limits->min_rate, limits->max_rate);
- limits->min_lane_count = 1;
+ limits->min_lane_count = intel_dp_min_lane_count(intel_dp);
limits->max_lane_count = intel_dp_max_lane_count(intel_dp);
limits->pipe.min_bpp = intel_dp_min_bpp(crtc_state->output_format);
@@ -2307,8 +2350,10 @@ intel_dp_compute_config_limits(struct intel_dp *intel_dp,
* configuration, and typically on older panels these
* values correspond to the native resolution of the panel.
*/
- limits->min_lane_count = limits->max_lane_count;
- limits->min_rate = limits->max_rate;
+ if (intel_dp->requested_lane_count == 0)
+ limits->min_lane_count = limits->max_lane_count;
+ if (intel_dp->requested_link_rate == 0)
+ limits->min_rate = limits->max_rate;
}
intel_dp_adjust_compliance_config(intel_dp, crtc_state, limits);
@@ -2947,7 +2992,7 @@ void intel_dp_set_link_params(struct intel_dp *intel_dp,
intel_dp->lane_count = lane_count;
}
-static void intel_dp_reset_link_train_params(struct intel_dp *intel_dp)
+void intel_dp_reset_link_train_params(struct intel_dp *intel_dp)
{
intel_dp->link_train.max_lane_count = intel_dp_max_common_lane_count(intel_dp);
intel_dp->link_train.max_rate = intel_dp_max_common_rate(intel_dp);
diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h
index 7c938327fc725..2b639bb2f56ed 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.h
+++ b/drivers/gpu/drm/i915/display/intel_dp.h
@@ -95,6 +95,7 @@ void intel_edp_backlight_off(const struct drm_connector_state *conn_state);
void intel_edp_fixup_vbt_bpp(struct intel_encoder *encoder, int pipe_bpp);
void intel_dp_mst_suspend(struct drm_i915_private *dev_priv);
void intel_dp_mst_resume(struct drm_i915_private *dev_priv);
+int intel_dp_max_source_lane_count(struct intel_digital_port *dig_port);
int intel_dp_max_link_rate(struct intel_dp *intel_dp);
int intel_dp_max_lane_count(struct intel_dp *intel_dp);
int intel_dp_config_required_rate(const struct intel_crtc_state *crtc_state);
@@ -104,6 +105,7 @@ int intel_dp_max_common_lane_count(struct intel_dp *intel_dp);
int intel_dp_common_rate(struct intel_dp *intel_dp, int index);
int intel_dp_rate_index(const int *rates, int len, int rate);
void intel_dp_update_sink_caps(struct intel_dp *intel_dp);
+void intel_dp_reset_link_train_params(struct intel_dp *intel_dp);
void intel_dp_compute_rate(struct intel_dp *intel_dp, int port_clock,
u8 *link_bw, u8 *rate_select);
diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
index b80fb25b9204d..352c77f46015e 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
@@ -1114,6 +1114,9 @@ static int reduce_link_rate(struct intel_dp *intel_dp, int current_rate)
int rate_index;
int new_rate;
+ if (intel_dp->requested_link_rate)
+ return -1;
+
rate_index = intel_dp_rate_index(intel_dp->common_rates,
intel_dp->num_common_rates,
current_rate);
@@ -1132,6 +1135,9 @@ static int reduce_link_rate(struct intel_dp *intel_dp, int current_rate)
static int reduce_lane_count(struct intel_dp *intel_dp, int current_lane_count)
{
+ if (intel_dp->requested_lane_count)
+ return -1;
+
if (current_lane_count > 1)
return current_lane_count >> 1;
--
2.43.3
