From: George Shen <George.Shen@xxxxxxx>
[Why]
Several issues were discovered that caused link
training to fail when an LTTPR device is
connected downstream for the fixed VS sequence.
[How]
The following were added:
- workaround to configure AUX timeout
for fixed VS sequence
- additional delay before disabling
fixed VS intercept
- detection of fixed VS deadlock state and
performing DPCD sequence to recover
Reviewed-by: Meenakshikumar Somasundaram <Meenakshikumar.Somasundaram@xxxxxxx>
Acked-by: Alan Liu <HaoPing.Liu@xxxxxxx>
Signed-off-by: George Shen <George.Shen@xxxxxxx>
---
.../gpu/drm/amd/display/dc/core/dc_link_dp.c | 43 ++++++++++++++++---
drivers/gpu/drm/amd/display/dc/dc.h | 2 +
.../drm/amd/display/dc/dcn31/dcn31_resource.c | 1 -
3 files changed, 40 insertions(+), 6 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 972dbbcc36da..c993b428ca7e 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
@@ -2384,6 +2384,7 @@ static enum link_training_result dp_perform_fixed_vs_pe_training_sequence(
link->dpcd_caps.lttpr_caps.phy_repeater_cnt);
const uint8_t vendor_lttpr_write_data_intercept_en[4] = {0x1, 0x55, 0x63, 0x0};
const uint8_t vendor_lttpr_write_data_intercept_dis[4] = {0x1, 0x55, 0x63, 0x68};
+ uint32_t pre_disable_intercept_delay_ms = link->dc->debug.fixed_vs_aux_delay_config_wa;
uint8_t vendor_lttpr_write_data_vs[4] = {0x1, 0x51, 0x63, 0x0};
uint8_t vendor_lttpr_write_data_pe[4] = {0x1, 0x52, 0x63, 0x0};
uint32_t vendor_lttpr_write_address = 0xF004F;
@@ -2406,6 +2407,10 @@ static enum link_training_result dp_perform_fixed_vs_pe_training_sequence(
if (offset != 0xFF) {
vendor_lttpr_write_address +=
((DP_REPEATER_CONFIGURATION_AND_STATUS_SIZE) * (offset - 1));
+
+ /* Certain display and cable configuration require extra delay */
+ if (offset > 2)
+ pre_disable_intercept_delay_ms = link->dc->debug.fixed_vs_aux_delay_config_wa * 2;
}
/* Vendor specific: Reset lane settings */
@@ -2485,6 +2490,7 @@ static enum link_training_result dp_perform_fixed_vs_pe_training_sequence(
/* Perform Clock Recovery Sequence */
if (status == LINK_TRAINING_SUCCESS) {
+ const uint8_t max_vendor_dpcd_retries = 10;
uint32_t retries_cr;
uint32_t retry_count;
uint32_t wait_time_microsec;
@@ -2492,6 +2498,8 @@ static enum link_training_result dp_perform_fixed_vs_pe_training_sequence(
union lane_status dpcd_lane_status[LANE_COUNT_DP_MAX];
union lane_align_status_updated dpcd_lane_status_updated;
union lane_adjust dpcd_lane_adjust[LANE_COUNT_DP_MAX] = {0};
+ enum dc_status dpcd_status = DC_OK;
+ uint8_t i = 0;
retries_cr = 0;
retry_count = 0;
@@ -2522,11 +2530,23 @@ static enum link_training_result dp_perform_fixed_vs_pe_training_sequence(
lt_settings->pattern_for_cr,
0);
/* Vendor specific: Disable intercept */
- core_link_write_dpcd(
- link,
- vendor_lttpr_write_address,
- &vendor_lttpr_write_data_intercept_dis[0],
- sizeof(vendor_lttpr_write_data_intercept_dis));
+ for (i = 0; i < max_vendor_dpcd_retries; i++) {
+ msleep(pre_disable_intercept_delay_ms);
+ dpcd_status = core_link_write_dpcd(
+ link,
+ vendor_lttpr_write_address,
+ &vendor_lttpr_write_data_intercept_dis[0],
+ sizeof(vendor_lttpr_write_data_intercept_dis));
+
+ if (dpcd_status == DC_OK)
+ break;
+
+ core_link_write_dpcd(
+ link,
+ vendor_lttpr_write_address,
+ &vendor_lttpr_write_data_intercept_en[0],
+ sizeof(vendor_lttpr_write_data_intercept_en));
+ }
} else {
vendor_lttpr_write_data_vs[3] = 0;
vendor_lttpr_write_data_pe[3] = 0;
@@ -5190,6 +5210,19 @@ bool dp_retrieve_lttpr_cap(struct dc_link *link)
determine_lttpr_mode(link);
if (link->lttpr_mode == LTTPR_MODE_NON_TRANSPARENT || link->lttpr_mode == LTTPR_MODE_TRANSPARENT) {
+ if ((link->chip_caps & EXT_DISPLAY_PATH_CAPS__DP_FIXED_VS_EN) &&
+ !link->dc->debug.disable_fixed_vs_aux_timeout_wa) {
+ /* Fixed VS workaround for AUX timeout */
+ const uint32_t fixed_vs_address = 0xF004F;
+ const uint8_t fixed_vs_data[4] = {0x1, 0x22, 0x63, 0xc};
+
+ core_link_write_dpcd(
+ link,
+ fixed_vs_address,
+ fixed_vs_data,
+ sizeof(fixed_vs_data));
+ }
+
/* By reading LTTPR capability, RX assumes that we will enable
* LTTPR extended aux timeout if LTTPR is present.
*/
diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index 51f5d75bf9e3..236a204d41ad 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -737,6 +737,8 @@ struct dc_debug_options {
bool enable_z9_disable_interface;
bool enable_sw_cntl_psr;
union dpia_debug_options dpia_debug;
+ bool disable_fixed_vs_aux_timeout_wa;
+ uint32_t fixed_vs_aux_delay_config_wa;
bool force_disable_subvp;
bool force_subvp_mclk_switch;
bool force_usr_allow;
diff --git a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c
index a67475251188..1a67d04cc017 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c
@@ -890,7 +890,6 @@ static const struct dc_debug_options debug_defaults_drv = {
.disable_z10 = true,
.optimize_edp_link_rate = true,
.enable_sw_cntl_psr = true,
- .apply_vendor_specific_lttpr_wa = true,
.enable_z9_disable_interface = true, /* Allow support for the PMFW interface for disable Z9*/
.dml_hostvm_override = DML_HOSTVM_OVERRIDE_FALSE,
};
--
2.25.1
