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drm/amd/display: force toggle rate wa for first link training for a retimer

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[WHY]
Handover from DMUB to driver does not perform link rate toggle.
It might cause link training failure for boot up.

[HOW]
Force toggle rate wa for first link train.
link->vendor_specific_lttpr_link_rate_wa should be zero then.

Cc: stable@vger.kernel.org # 6.1+
Reviewed-by: Michael Strauss <michael.strauss@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Zhongwei <zhongwei.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Zhongwei 2023-11-08 16:34:36 +08:00 committed by Alex Deucher
parent c6df7f3137
commit eb28018943
1 changed files with 3 additions and 3 deletions
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6
drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_fixed_vs_pe_retimer.c
View File

@ -115,7 +115,7 @@ static enum link_training_result perform_fixed_vs_pe_nontransparent_training_seq
lt_settings->cr_pattern_time = 16000;
/* Fixed VS/PE specific: Toggle link rate */
apply_toggle_rate_wa = (link->vendor_specific_lttpr_link_rate_wa == target_rate);
apply_toggle_rate_wa = ((link->vendor_specific_lttpr_link_rate_wa == target_rate) || (link->vendor_specific_lttpr_link_rate_wa == 0));
target_rate = get_dpcd_link_rate(&lt_settings->link_settings);
toggle_rate = (target_rate == 0x6) ? 0xA : 0x6;
@ -271,7 +271,7 @@ enum link_training_result dp_perform_fixed_vs_pe_training_sequence_legacy(
/* Vendor specific: Toggle link rate */
toggle_rate = (rate == 0x6) ? 0xA : 0x6;
if (link->vendor_specific_lttpr_link_rate_wa == rate) {
if (link->vendor_specific_lttpr_link_rate_wa == rate || link->vendor_specific_lttpr_link_rate_wa == 0) {
core_link_write_dpcd(
link,
DP_LINK_BW_SET,
@ -617,7 +617,7 @@ enum link_training_result dp_perform_fixed_vs_pe_training_sequence(
/* Vendor specific: Toggle link rate */
toggle_rate = (rate == 0x6) ? 0xA : 0x6;
if (link->vendor_specific_lttpr_link_rate_wa == rate) {
if (link->vendor_specific_lttpr_link_rate_wa == rate || link->vendor_specific_lttpr_link_rate_wa == 0) {
core_link_write_dpcd(
link,
DP_LINK_BW_SET,