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authorJani Nikula <jani.nikula@intel.com>2019-06-13 11:44:15 +0300
committerJani Nikula <jani.nikula@intel.com>2019-06-17 11:25:06 +0300
commit379bc100232acd45b19421bd0748f9f549da8a8a (patch)
tree86834fab64b369d73ec634e48c588a9a7237264c /drivers/gpu/drm/i915/display/intel_dp_link_training.c
parentca851bae0f525ba5a9f75b1644acccb57f88aabf (diff)
drm/i915: move modesetting output/encoder code under display/
Add a new subdirectory for display code, and start off by moving modesetting output/encoder code. Judging by the include changes, this is a surprisingly clean operation. v2: - move intel_sdvo_regs.h too - use tabs for Makefile file lists and sort them Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190613084416.6794-2-jani.nikula@intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/display/intel_dp_link_training.c')
-rw-r--r--drivers/gpu/drm/i915/display/intel_dp_link_training.c382
1 files changed, 382 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
new file mode 100644
index 000000000000..9b1fccea966b
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
@@ -0,0 +1,382 @@
+/*
+ * Copyright © 2008-2015 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "intel_dp.h"
+#include "intel_dp_link_training.h"
+#include "intel_drv.h"
+
+static void
+intel_dp_dump_link_status(const u8 link_status[DP_LINK_STATUS_SIZE])
+{
+
+ DRM_DEBUG_KMS("ln0_1:0x%x ln2_3:0x%x align:0x%x sink:0x%x adj_req0_1:0x%x adj_req2_3:0x%x",
+ link_status[0], link_status[1], link_status[2],
+ link_status[3], link_status[4], link_status[5]);
+}
+
+static void
+intel_get_adjust_train(struct intel_dp *intel_dp,
+ const u8 link_status[DP_LINK_STATUS_SIZE])
+{
+ u8 v = 0;
+ u8 p = 0;
+ int lane;
+ u8 voltage_max;
+ u8 preemph_max;
+
+ for (lane = 0; lane < intel_dp->lane_count; lane++) {
+ u8 this_v = drm_dp_get_adjust_request_voltage(link_status, lane);
+ u8 this_p = drm_dp_get_adjust_request_pre_emphasis(link_status, lane);
+
+ if (this_v > v)
+ v = this_v;
+ if (this_p > p)
+ p = this_p;
+ }
+
+ voltage_max = intel_dp_voltage_max(intel_dp);
+ if (v >= voltage_max)
+ v = voltage_max | DP_TRAIN_MAX_SWING_REACHED;
+
+ preemph_max = intel_dp_pre_emphasis_max(intel_dp, v);
+ if (p >= preemph_max)
+ p = preemph_max | DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
+
+ for (lane = 0; lane < 4; lane++)
+ intel_dp->train_set[lane] = v | p;
+}
+
+static bool
+intel_dp_set_link_train(struct intel_dp *intel_dp,
+ u8 dp_train_pat)
+{
+ u8 buf[sizeof(intel_dp->train_set) + 1];
+ int ret, len;
+
+ intel_dp_program_link_training_pattern(intel_dp, dp_train_pat);
+
+ buf[0] = dp_train_pat;
+ if ((dp_train_pat & DP_TRAINING_PATTERN_MASK) ==
+ DP_TRAINING_PATTERN_DISABLE) {
+ /* don't write DP_TRAINING_LANEx_SET on disable */
+ len = 1;
+ } else {
+ /* DP_TRAINING_LANEx_SET follow DP_TRAINING_PATTERN_SET */
+ memcpy(buf + 1, intel_dp->train_set, intel_dp->lane_count);
+ len = intel_dp->lane_count + 1;
+ }
+
+ ret = drm_dp_dpcd_write(&intel_dp->aux, DP_TRAINING_PATTERN_SET,
+ buf, len);
+
+ return ret == len;
+}
+
+static bool
+intel_dp_reset_link_train(struct intel_dp *intel_dp,
+ u8 dp_train_pat)
+{
+ memset(intel_dp->train_set, 0, sizeof(intel_dp->train_set));
+ intel_dp_set_signal_levels(intel_dp);
+ return intel_dp_set_link_train(intel_dp, dp_train_pat);
+}
+
+static bool
+intel_dp_update_link_train(struct intel_dp *intel_dp)
+{
+ int ret;
+
+ intel_dp_set_signal_levels(intel_dp);
+
+ ret = drm_dp_dpcd_write(&intel_dp->aux, DP_TRAINING_LANE0_SET,
+ intel_dp->train_set, intel_dp->lane_count);
+
+ return ret == intel_dp->lane_count;
+}
+
+static bool intel_dp_link_max_vswing_reached(struct intel_dp *intel_dp)
+{
+ int lane;
+
+ for (lane = 0; lane < intel_dp->lane_count; lane++)
+ if ((intel_dp->train_set[lane] &
+ DP_TRAIN_MAX_SWING_REACHED) == 0)
+ return false;
+
+ return true;
+}
+
+/* Enable corresponding port and start training pattern 1 */
+static bool
+intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp)
+{
+ u8 voltage;
+ int voltage_tries, cr_tries, max_cr_tries;
+ bool max_vswing_reached = false;
+ u8 link_config[2];
+ u8 link_bw, rate_select;
+
+ if (intel_dp->prepare_link_retrain)
+ intel_dp->prepare_link_retrain(intel_dp);
+
+ intel_dp_compute_rate(intel_dp, intel_dp->link_rate,
+ &link_bw, &rate_select);
+
+ if (link_bw)
+ DRM_DEBUG_KMS("Using LINK_BW_SET value %02x\n", link_bw);
+ else
+ DRM_DEBUG_KMS("Using LINK_RATE_SET value %02x\n", rate_select);
+
+ /* Write the link configuration data */
+ link_config[0] = link_bw;
+ link_config[1] = intel_dp->lane_count;
+ if (drm_dp_enhanced_frame_cap(intel_dp->dpcd))
+ link_config[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
+ drm_dp_dpcd_write(&intel_dp->aux, DP_LINK_BW_SET, link_config, 2);
+
+ /* eDP 1.4 rate select method. */
+ if (!link_bw)
+ drm_dp_dpcd_write(&intel_dp->aux, DP_LINK_RATE_SET,
+ &rate_select, 1);
+
+ link_config[0] = 0;
+ link_config[1] = DP_SET_ANSI_8B10B;
+ drm_dp_dpcd_write(&intel_dp->aux, DP_DOWNSPREAD_CTRL, link_config, 2);
+
+ intel_dp->DP |= DP_PORT_EN;
+
+ /* clock recovery */
+ if (!intel_dp_reset_link_train(intel_dp,
+ DP_TRAINING_PATTERN_1 |
+ DP_LINK_SCRAMBLING_DISABLE)) {
+ DRM_ERROR("failed to enable link training\n");
+ return false;
+ }
+
+ /*
+ * The DP 1.4 spec defines the max clock recovery retries value
+ * as 10 but for pre-DP 1.4 devices we set a very tolerant
+ * retry limit of 80 (4 voltage levels x 4 preemphasis levels x
+ * x 5 identical voltage retries). Since the previous specs didn't
+ * define a limit and created the possibility of an infinite loop
+ * we want to prevent any sync from triggering that corner case.
+ */
+ if (intel_dp->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14)
+ max_cr_tries = 10;
+ else
+ max_cr_tries = 80;
+
+ voltage_tries = 1;
+ for (cr_tries = 0; cr_tries < max_cr_tries; ++cr_tries) {
+ u8 link_status[DP_LINK_STATUS_SIZE];
+
+ drm_dp_link_train_clock_recovery_delay(intel_dp->dpcd);
+
+ if (!intel_dp_get_link_status(intel_dp, link_status)) {
+ DRM_ERROR("failed to get link status\n");
+ return false;
+ }
+
+ if (drm_dp_clock_recovery_ok(link_status, intel_dp->lane_count)) {
+ DRM_DEBUG_KMS("clock recovery OK\n");
+ return true;
+ }
+
+ if (voltage_tries == 5) {
+ DRM_DEBUG_KMS("Same voltage tried 5 times\n");
+ return false;
+ }
+
+ if (max_vswing_reached) {
+ DRM_DEBUG_KMS("Max Voltage Swing reached\n");
+ return false;
+ }
+
+ voltage = intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
+
+ /* Update training set as requested by target */
+ intel_get_adjust_train(intel_dp, link_status);
+ if (!intel_dp_update_link_train(intel_dp)) {
+ DRM_ERROR("failed to update link training\n");
+ return false;
+ }
+
+ if ((intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) ==
+ voltage)
+ ++voltage_tries;
+ else
+ voltage_tries = 1;
+
+ if (intel_dp_link_max_vswing_reached(intel_dp))
+ max_vswing_reached = true;
+
+ }
+ DRM_ERROR("Failed clock recovery %d times, giving up!\n", max_cr_tries);
+ return false;
+}
+
+/*
+ * Pick training pattern for channel equalization. Training pattern 4 for HBR3
+ * or for 1.4 devices that support it, training Pattern 3 for HBR2
+ * or 1.2 devices that support it, Training Pattern 2 otherwise.
+ */
+static u32 intel_dp_training_pattern(struct intel_dp *intel_dp)
+{
+ bool source_tps3, sink_tps3, source_tps4, sink_tps4;
+
+ /*
+ * Intel platforms that support HBR3 also support TPS4. It is mandatory
+ * for all downstream devices that support HBR3. There are no known eDP
+ * panels that support TPS4 as of Feb 2018 as per VESA eDP_v1.4b_E1
+ * specification.
+ */
+ source_tps4 = intel_dp_source_supports_hbr3(intel_dp);
+ sink_tps4 = drm_dp_tps4_supported(intel_dp->dpcd);
+ if (source_tps4 && sink_tps4) {
+ return DP_TRAINING_PATTERN_4;
+ } else if (intel_dp->link_rate == 810000) {
+ if (!source_tps4)
+ DRM_DEBUG_KMS("8.1 Gbps link rate without source HBR3/TPS4 support\n");
+ if (!sink_tps4)
+ DRM_DEBUG_KMS("8.1 Gbps link rate without sink TPS4 support\n");
+ }
+ /*
+ * Intel platforms that support HBR2 also support TPS3. TPS3 support is
+ * also mandatory for downstream devices that support HBR2. However, not
+ * all sinks follow the spec.
+ */
+ source_tps3 = intel_dp_source_supports_hbr2(intel_dp);
+ sink_tps3 = drm_dp_tps3_supported(intel_dp->dpcd);
+ if (source_tps3 && sink_tps3) {
+ return DP_TRAINING_PATTERN_3;
+ } else if (intel_dp->link_rate >= 540000) {
+ if (!source_tps3)
+ DRM_DEBUG_KMS(">=5.4/6.48 Gbps link rate without source HBR2/TPS3 support\n");
+ if (!sink_tps3)
+ DRM_DEBUG_KMS(">=5.4/6.48 Gbps link rate without sink TPS3 support\n");
+ }
+
+ return DP_TRAINING_PATTERN_2;
+}
+
+static bool
+intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp)
+{
+ int tries;
+ u32 training_pattern;
+ u8 link_status[DP_LINK_STATUS_SIZE];
+ bool channel_eq = false;
+
+ training_pattern = intel_dp_training_pattern(intel_dp);
+ /* Scrambling is disabled for TPS2/3 and enabled for TPS4 */
+ if (training_pattern != DP_TRAINING_PATTERN_4)
+ training_pattern |= DP_LINK_SCRAMBLING_DISABLE;
+
+ /* channel equalization */
+ if (!intel_dp_set_link_train(intel_dp,
+ training_pattern)) {
+ DRM_ERROR("failed to start channel equalization\n");
+ return false;
+ }
+
+ for (tries = 0; tries < 5; tries++) {
+
+ drm_dp_link_train_channel_eq_delay(intel_dp->dpcd);
+ if (!intel_dp_get_link_status(intel_dp, link_status)) {
+ DRM_ERROR("failed to get link status\n");
+ break;
+ }
+
+ /* Make sure clock is still ok */
+ if (!drm_dp_clock_recovery_ok(link_status,
+ intel_dp->lane_count)) {
+ intel_dp_dump_link_status(link_status);
+ DRM_DEBUG_KMS("Clock recovery check failed, cannot "
+ "continue channel equalization\n");
+ break;
+ }
+
+ if (drm_dp_channel_eq_ok(link_status,
+ intel_dp->lane_count)) {
+ channel_eq = true;
+ DRM_DEBUG_KMS("Channel EQ done. DP Training "
+ "successful\n");
+ break;
+ }
+
+ /* Update training set as requested by target */
+ intel_get_adjust_train(intel_dp, link_status);
+ if (!intel_dp_update_link_train(intel_dp)) {
+ DRM_ERROR("failed to update link training\n");
+ break;
+ }
+ }
+
+ /* Try 5 times, else fail and try at lower BW */
+ if (tries == 5) {
+ intel_dp_dump_link_status(link_status);
+ DRM_DEBUG_KMS("Channel equalization failed 5 times\n");
+ }
+
+ intel_dp_set_idle_link_train(intel_dp);
+
+ return channel_eq;
+
+}
+
+void intel_dp_stop_link_train(struct intel_dp *intel_dp)
+{
+ intel_dp->link_trained = true;
+
+ intel_dp_set_link_train(intel_dp,
+ DP_TRAINING_PATTERN_DISABLE);
+}
+
+void
+intel_dp_start_link_train(struct intel_dp *intel_dp)
+{
+ struct intel_connector *intel_connector = intel_dp->attached_connector;
+
+ if (!intel_dp_link_training_clock_recovery(intel_dp))
+ goto failure_handling;
+ if (!intel_dp_link_training_channel_equalization(intel_dp))
+ goto failure_handling;
+
+ DRM_DEBUG_KMS("[CONNECTOR:%d:%s] Link Training Passed at Link Rate = %d, Lane count = %d",
+ intel_connector->base.base.id,
+ intel_connector->base.name,
+ intel_dp->link_rate, intel_dp->lane_count);
+ return;
+
+ failure_handling:
+ DRM_DEBUG_KMS("[CONNECTOR:%d:%s] Link Training failed at link rate = %d, lane count = %d",
+ intel_connector->base.base.id,
+ intel_connector->base.name,
+ intel_dp->link_rate, intel_dp->lane_count);
+ if (!intel_dp_get_link_train_fallback_values(intel_dp,
+ intel_dp->link_rate,
+ intel_dp->lane_count))
+ /* Schedule a Hotplug Uevent to userspace to start modeset */
+ schedule_work(&intel_connector->modeset_retry_work);
+ return;
+}