[PATCH 11/15] drm/amd/display: add a debug option to force dp2 lt fallback method
Pavle Kotarac
Pavle.Kotarac at amd.com
Fri Dec 3 22:57:58 UTC 2021
From: Wenjing Liu <wenjing.liu at amd.com>
[why]
A debug option is needed to temporarily force dp2 new link training
fallback method for debugging purpose.
Reviewed-by: George Shen <George.Shen at amd.com>
Acked-by: Pavle Kotarac <Pavle.Kotarac at amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu at amd.com>
---
drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 9 ++++++---
drivers/gpu/drm/amd/display/dc/dc.h | 1 +
2 files changed, 7 insertions(+), 3 deletions(-)
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 f1898f1c9e22..56e141fb2694 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
@@ -100,6 +100,7 @@ static const struct dp_lt_fallback_entry dp_lt_fallbacks[] = {
#endif
static bool decide_fallback_link_setting(
+ struct dc_link *link,
struct dc_link_settings initial_link_settings,
struct dc_link_settings *current_link_setting,
enum link_training_result training_result);
@@ -2609,7 +2610,7 @@ bool perform_link_training_with_retries(
uint32_t req_bw;
uint32_t link_bw;
- decide_fallback_link_setting(*link_setting, ¤t_setting, status);
+ decide_fallback_link_setting(link, *link_setting, ¤t_setting, status);
/* Fail link training if reduced link bandwidth no longer meets
* stream requirements.
*/
@@ -3124,7 +3125,7 @@ bool dp_verify_link_cap(
* based on the actual mode we're driving
*/
dp_disable_link_phy(link, link->connector_signal);
- } while (!success && decide_fallback_link_setting(
+ } while (!success && decide_fallback_link_setting(link,
initial_link_settings, cur, status));
/* Link Training failed for all Link Settings
@@ -3376,6 +3377,7 @@ static bool decide_fallback_link_setting_max_bw_policy(
* and no further fallback could be done
*/
static bool decide_fallback_link_setting(
+ struct dc_link *link,
struct dc_link_settings initial_link_settings,
struct dc_link_settings *current_link_setting,
enum link_training_result training_result)
@@ -3383,7 +3385,8 @@ static bool decide_fallback_link_setting(
if (!current_link_setting)
return false;
#if defined(CONFIG_DRM_AMD_DC_DCN)
- if (dp_get_link_encoding_format(&initial_link_settings) == DP_128b_132b_ENCODING)
+ if (dp_get_link_encoding_format(&initial_link_settings) == DP_128b_132b_ENCODING ||
+ link->dc->debug.force_dp2_lt_fallback_method)
return decide_fallback_link_setting_max_bw_policy(&initial_link_settings,
current_link_setting);
#endif
diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index 5c2cb892d993..a43c008bd0f2 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -691,6 +691,7 @@ struct dc_debug_options {
/* TODO - remove once tested */
bool legacy_dp2_lt;
bool set_mst_en_for_sst;
+ bool force_dp2_lt_fallback_method;
#endif
union mem_low_power_enable_options enable_mem_low_power;
union root_clock_optimization_options root_clock_optimization;
--
2.32.0
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