From: Jimmy Kizito <jimmy.kiz...@amd.com>
[Why]
When enabling a DisplayPort stream:
- Optionally reducing link bandwidth between failed link training
attempts should progressively relax training requirements.
- Abandoning link training altogether if a sink is unplugged should
avoid unnecessary training attempts.
[How]
- Add fallback parameter to DP link training function and reduce link
bandwidth between failed training attempts as long as stream bandwidth
requirements are met.
- Add training status for sink unplug and abort training when this
status is reported.
Signed-off-by: Jimmy Kizito <jimmy.kiz...@amd.com>
Reviewed-by: Jun Lei <jun....@amd.com>
Acked-by: Stylon Wang <stylon.w...@amd.com>
---
drivers/gpu/drm/amd/display/dc/core/dc_link.c | 5 ++-
.../gpu/drm/amd/display/dc/core/dc_link_dp.c | 40 +++++++++++++++----
.../drm/amd/display/dc/core/dc_link_hwss.c | 3 +-
.../gpu/drm/amd/display/dc/inc/dc_link_dp.h | 3 +-
.../amd/display/include/link_service_types.h | 2 +
5 files changed, 42 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
index d040d235c2db..c4405eba724c 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -1750,6 +1750,8 @@ static enum dc_status enable_link_dp(struct dc_state
*state,
bool apply_seamless_boot_optimization = false;
uint32_t bl_oled_enable_delay = 50; // in ms
const uint32_t post_oui_delay = 30; // 30ms
+ /* Reduce link bandwidth between failed link training attempts. */
+ bool do_fallback = false;
// check for seamless boot
for (i = 0; i < state->stream_count; i++) {
@@ -1788,7 +1790,8 @@ static enum dc_status enable_link_dp(struct dc_state
*state,
skip_video_pattern,
LINK_TRAINING_ATTEMPTS,
pipe_ctx,
- pipe_ctx->stream->signal)) {
+ pipe_ctx->stream->signal,
+ do_fallback)) {
link->cur_link_settings = link_settings;
status = DC_OK;
} else {
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index 8565281e6179..b6ed57ba7a48 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -1701,18 +1701,31 @@ bool perform_link_training_with_retries(
bool skip_video_pattern,
int attempts,
struct pipe_ctx *pipe_ctx,
- enum signal_type signal)
+ enum signal_type signal,
+ bool do_fallback)
{
uint8_t j;
uint8_t delay_between_attempts = LINK_TRAINING_RETRY_DELAY;
struct dc_stream_state *stream = pipe_ctx->stream;
struct dc_link *link = stream->link;
enum dp_panel_mode panel_mode;
+ struct link_encoder *link_enc;
+ enum link_training_result status = LINK_TRAINING_CR_FAIL_LANE0;
+ struct dc_link_settings currnet_setting = *link_setting;
+
+ /* Dynamically assigned link encoders associated with stream rather than
+ * link.
+ */
+ if (link->dc->res_pool->funcs->link_encs_assign)
+ link_enc = stream->link_enc;
+ else
+ link_enc = link->link_enc;
+ ASSERT(link_enc);
/* We need to do this before the link training to ensure the idle
pattern in SST
* mode will be sent right after the link training
*/
- link->link_enc->funcs->connect_dig_be_to_fe(link->link_enc,
+ link_enc->funcs->connect_dig_be_to_fe(link_enc,
pipe_ctx->stream_res.stream_enc->id, true);
for (j = 0; j < attempts; ++j) {
@@ -1724,7 +1737,7 @@ bool perform_link_training_with_retries(
link,
signal,
pipe_ctx->clock_source->id,
- link_setting);
+ &currnet_setting);
if (stream->sink_patches.dppowerup_delay > 0) {
int delay_dp_power_up_in_ms =
stream->sink_patches.dppowerup_delay;
@@ -1739,14 +1752,12 @@ bool perform_link_training_with_retries(
panel_mode != DP_PANEL_MODE_DEFAULT);
if (link->aux_access_disabled) {
- dc_link_dp_perform_link_training_skip_aux(link,
link_setting);
+ dc_link_dp_perform_link_training_skip_aux(link,
&currnet_setting);
return true;
} else {
- enum link_training_result status =
LINK_TRAINING_CR_FAIL_LANE0;
-
status = dc_link_dp_perform_link_training(
link,
-
link_setting,
+
&currnet_setting,
skip_video_pattern);
if (status == LINK_TRAINING_SUCCESS)
return true;
@@ -1754,7 +1765,7 @@ bool perform_link_training_with_retries(
/* latest link training still fail, skip delay and keep PHY on
*/
- if (j == (attempts - 1))
+ if (j == (attempts - 1) && link->ep_type ==
DISPLAY_ENDPOINT_PHY)
break;
DC_LOG_WARNING("%s: Link training attempt %u of %d failed\n",
@@ -1762,6 +1773,19 @@ bool perform_link_training_with_retries(
dp_disable_link_phy(link, signal);
+ /* Abort link training if failure due to sink being unplugged.
*/
+ if (status == LINK_TRAINING_ABORT)
+ break;
+ else if (do_fallback) {
+ decide_fallback_link_setting(*link_setting,
&currnet_setting, status);
+ /* Fail link training if reduced link bandwidth no
longer meets
+ * stream requirements.
+ */
+ if (dc_bandwidth_in_kbps_from_timing(&stream->timing) <
+ dc_link_bandwidth_kbps(link,
&currnet_setting))
+ break;
+ }
+
msleep(delay_between_attempts);
delay_between_attempts += LINK_TRAINING_RETRY_DELAY;
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_hwss.c
b/drivers/gpu/drm/amd/display/dc/core/dc_link_hwss.c
index b426f878fb99..13c5c4a34a58 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_hwss.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_hwss.c
@@ -384,7 +384,8 @@ void dp_retrain_link_dp_test(struct dc_link *link,
skip_video_pattern,
LINK_TRAINING_ATTEMPTS,
&pipes[i],
- SIGNAL_TYPE_DISPLAY_PORT);
+ SIGNAL_TYPE_DISPLAY_PORT,
+ false);
link->dc->hwss.enable_stream(&pipes[i]);
diff --git a/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h
b/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h
index 699de64a7e44..38e6fbf1e26d 100644
--- a/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h
@@ -65,7 +65,8 @@ bool perform_link_training_with_retries(
bool skip_video_pattern,
int attempts,
struct pipe_ctx *pipe_ctx,
- enum signal_type signal);
+ enum signal_type signal,
+ bool do_fallback);
bool is_mst_supported(struct dc_link *link);
diff --git a/drivers/gpu/drm/amd/display/include/link_service_types.h
b/drivers/gpu/drm/amd/display/include/link_service_types.h
index 7392a89e771f..5a250f41004f 100644
--- a/drivers/gpu/drm/amd/display/include/link_service_types.h
+++ b/drivers/gpu/drm/amd/display/include/link_service_types.h
@@ -68,6 +68,8 @@ enum link_training_result {
LINK_TRAINING_LQA_FAIL,
/* one of the CR,EQ or symbol lock is dropped */
LINK_TRAINING_LINK_LOSS,
+ /* Abort link training (because sink unplugged) */
+ LINK_TRAINING_ABORT,
};
struct link_training_settings {
--
2.25.1
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