On Thu, May 23, 2024 at 06:25:08PM +0300, Ville Syrjälä wrote: > On Mon, May 20, 2024 at 09:58:15PM +0300, Imre Deak wrote: > > 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. > > > > v2: > > - Add the entries from intel_dp_link_training.c (Jani) > > - Rename the entries to i915_dp_set_link_rate/lane_count. > > > > Cc: Jani Nikula <jani.nikula@xxxxxxxxx> > > Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx> > > --- > > .../drm/i915/display/intel_display_debugfs.c | 2 + > > .../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 | 230 ++++++++++++++++++ > > .../drm/i915/display/intel_dp_link_training.h | 4 + > > 6 files changed, 294 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..f83ffa2534925 100644 > > --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c > > +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c > > @@ -23,6 +23,7 @@ > > #include "intel_display_types.h" > > #include "intel_dmc.h" > > #include "intel_dp.h" > > +#include "intel_dp_link_training.h" > > #include "intel_dp_mst.h" > > #include "intel_drrs.h" > > #include "intel_fbc.h" > > @@ -1515,6 +1516,7 @@ void intel_connector_debugfs_add(struct intel_connector *connector) > > intel_drrs_connector_debugfs_add(connector); > > intel_pps_connector_debugfs_add(connector); > > intel_psr_connector_debugfs_add(connector); > > + intel_dp_link_training_debugfs_add(connector); > > > > if (connector_type == DRM_MODE_CONNECTOR_DisplayPort || > > connector_type == DRM_MODE_CONNECTOR_HDMIA || > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h > > index eb0cac3e27acf..e1c41cece249d 100644 > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h > > @@ -1765,6 +1765,8 @@ struct intel_dp { > > int max_lane_count; > > /* Max rate for the current link */ > > int max_rate; > > + int requested_lane_count; > > + int requested_rate; > > "requested" is perhaps a bit weak. Maybe "force" or "override" > although perhaps those might give the impression that it ignores > the sink limits or something? It determines the rate/lane count within the valid common range. Can rename it to force. > > > bool retrain_disabled; > > /* Sequential link training failures after a passing LT */ > > int seq_train_failures; > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c > > index c8d940a2ef7af..cf4a768fccd15 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->link.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.max_lane_count) { > > + int lane_count; > > + > > + if (intel_dp->link.requested_lane_count) > > + lane_count = requested_lane_count(intel_dp); > > + else > > + lane_count = intel_dp->link.max_lane_count; > > + > > + switch (lane_count) { > > case 1: > > case 2: > > case 4: > > - return intel_dp->link.max_lane_count; > > + return lane_count; > > default: > > - MISSING_CASE(intel_dp->link.max_lane_count); > > + MISSING_CASE(lane_count); > > return 1; > > } > > } > > > > +static int intel_dp_min_lane_count(struct intel_dp *intel_dp) > > +{ > > + if (intel_dp->link.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->link.requested_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->link.requested_rate) > > + return requested_rate(intel_dp); > > + > > len = intel_dp_common_len_rate_limit(intel_dp, intel_dp->link.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->link.requested_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->link.requested_lane_count == 0) > > + limits->min_lane_count = limits->max_lane_count; > > + if (intel_dp->link.requested_rate == 0) > > + limits->min_rate = limits->max_rate; > > Aren't the min and max the same anyway if the debugfs override is in > use? Yes, thanks for spotting that, this eDP override can stay as-is. > > } > > > > intel_dp_adjust_compliance_config(intel_dp, crtc_state, limits); > > @@ -2946,7 +2991,7 @@ void intel_dp_set_link_params(struct intel_dp *intel_dp, > > intel_dp->lane_count = lane_count; > > } > > > > -static void intel_dp_reset_link_params(struct intel_dp *intel_dp) > > +void intel_dp_reset_link_params(struct intel_dp *intel_dp) > > { > > intel_dp->link.max_lane_count = intel_dp_max_common_lane_count(intel_dp); > > intel_dp->link.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 3fa53ac601d58..79914e5080251 100644 > > --- a/drivers/gpu/drm/i915/display/intel_dp.h > > +++ b/drivers/gpu/drm/i915/display/intel_dp.h > > @@ -99,6 +99,7 @@ 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); > > @@ -108,6 +109,7 @@ 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_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 9a59a28ca36d2..a6021e17cc1ef 100644 > > --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c > > +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c > > @@ -1115,6 +1115,9 @@ static int reduce_link_rate(struct intel_dp *intel_dp, int current_rate) > > int rate_index; > > int new_rate; > > > > + if (intel_dp->link.requested_rate) > > + return -1; > > + > > rate_index = intel_dp_rate_index(intel_dp->common_rates, > > intel_dp->num_common_rates, > > current_rate); > > @@ -1133,6 +1136,9 @@ 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->link.requested_lane_count) > > + return -1; > > + > > if (current_lane_count > 1) > > return current_lane_count >> 1; > > > > @@ -1543,3 +1549,227 @@ void intel_dp_128b132b_sdp_crc16(struct intel_dp *intel_dp, > > > > lt_dbg(intel_dp, DP_PHY_DPRX, "DP2.0 SDP CRC16 for 128b/132b enabled\n"); > > } > > + > > +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_set_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); > > What is this lock protecting exactly? The connector state, for instace from getting removed after a disconnect event and the link caps in intel_dp. > > > + if (ret) > > + return ret; > > + > > + intel_dp = intel_connector_to_intel_dp(connector); > > + > > + seq_printf(m, "%sauto%s", > > + intel_dp->link.requested_rate == 0 ? "[" : "", > > + intel_dp->link.requested_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->link.requested_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->link.requested_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_set_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_params(intel_dp); > > + intel_dp->link.requested_rate = rate; > > + > > + drm_modeset_unlock(&i915->drm.mode_config.connection_mutex); > > + > > + *offp += len; > > + > > + return len; > > +} > > +DEFINE_SHOW_STORE_ATTRIBUTE(i915_dp_set_link_rate); > > + > > +static int i915_dp_set_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->link.requested_lane_count == 0 ? "[" : "", > > + intel_dp->link.requested_lane_count == 0 ? "]" : ""); > > + > > + for (i = 1; i <= 4; i <<= 1) > > + seq_printf(m, " %s%d%s%s", > > + i == intel_dp->link.requested_lane_count ? "[" : "", > > + i, > > + intel_dp->link_trained && > > + i == intel_dp->lane_count ? "*" : "", > > + i == intel_dp->link.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_set_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_params(intel_dp); > > + intel_dp->link.requested_lane_count = lane_count; > > + > > + drm_modeset_unlock(&i915->drm.mode_config.connection_mutex); > > + > > + *offp += len; > > + > > + return len; > > +} > > +DEFINE_SHOW_STORE_ATTRIBUTE(i915_dp_set_lane_count); > > + > > +void intel_dp_link_training_debugfs_add(struct intel_connector *connector) > > +{ > > + struct dentry *root = connector->base.debugfs_entry; > > + > > + if (connector->base.connector_type != DRM_MODE_CONNECTOR_DisplayPort && > > + connector->base.connector_type != DRM_MODE_CONNECTOR_eDP) > > + return; > > + > > + debugfs_create_file("i915_dp_set_link_rate", 0644, root, > > + connector, &i915_dp_set_link_rate_fops); > > + > > + debugfs_create_file("i915_dp_set_lane_count", 0644, root, > > + connector, &i915_dp_set_lane_count_fops); > > +} > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.h b/drivers/gpu/drm/i915/display/intel_dp_link_training.h > > index f658230960333..42e7fc6cb171a 100644 > > --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.h > > +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.h > > @@ -9,6 +9,7 @@ > > #include <drm/display/drm_dp_helper.h> > > > > struct intel_atomic_state; > > +struct intel_connector; > > struct intel_crtc_state; > > struct intel_dp; > > > > @@ -44,4 +45,7 @@ static inline u8 intel_dp_training_pattern_symbol(u8 pattern) > > > > void intel_dp_128b132b_sdp_crc16(struct intel_dp *intel_dp, > > const struct intel_crtc_state *crtc_state); > > + > > +void intel_dp_link_training_debugfs_add(struct intel_connector *connector); > > + > > #endif /* __INTEL_DP_LINK_TRAINING_H__ */ > > -- > > 2.43.3 > > -- > Ville Syrjälä > Intel