summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorVladimir Stempen <vladimir.stempen@amd.com>2020-04-28 13:04:35 -0400
committerAlex Deucher <alexander.deucher@amd.com>2020-05-20 17:23:51 -0400
commitb6ef55ccba7ed00fc10e3e6f619c8f886162427f (patch)
tree57044057679110f5b68ffab00be7529f8675c992
parent5a3f610877e9d08968ea7237551049581f02b163 (diff)
downloadlinux-b6ef55ccba7ed00fc10e3e6f619c8f886162427f.tar.bz2
drm/amd/display: DP training to set properly SCRAMBLING_DISABLE
[Why] DP training sequence to set SCRAMBLING_DISABLE bit properly based on training pattern - per DP Spec. [How] Update dpcd_pattern.v1_4.SCRAMBLING_DISABLE with 1 for TPS1, TPS2, TPS3, but not for TPS4. Signed-off-by: Vladimir Stempen <vladimir.stempen@amd.com> Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com> Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
-rw-r--r--drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c27
1 files changed, 27 insertions, 0 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 27a7d2a58079..caa090d0b6ac 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
@@ -220,6 +220,30 @@ static enum dpcd_training_patterns
return dpcd_tr_pattern;
}
+static uint8_t dc_dp_initialize_scrambling_data_symbols(
+ struct dc_link *link,
+ enum dc_dp_training_pattern pattern)
+{
+ uint8_t disable_scrabled_data_symbols = 0;
+
+ switch (pattern) {
+ case DP_TRAINING_PATTERN_SEQUENCE_1:
+ case DP_TRAINING_PATTERN_SEQUENCE_2:
+ case DP_TRAINING_PATTERN_SEQUENCE_3:
+ disable_scrabled_data_symbols = 1;
+ break;
+ case DP_TRAINING_PATTERN_SEQUENCE_4:
+ disable_scrabled_data_symbols = 0;
+ break;
+ default:
+ ASSERT(0);
+ DC_LOG_HW_LINK_TRAINING("%s: Invalid HW Training pattern: %d\n",
+ __func__, pattern);
+ break;
+ }
+ return disable_scrabled_data_symbols;
+}
+
static inline bool is_repeater(struct dc_link *link, uint32_t offset)
{
return (!link->is_lttpr_mode_transparent && offset != 0);
@@ -252,6 +276,9 @@ static void dpcd_set_lt_pattern_and_lane_settings(
dpcd_pattern.v1_4.TRAINING_PATTERN_SET =
dc_dp_training_pattern_to_dpcd_training_pattern(link, pattern);
+ dpcd_pattern.v1_4.SCRAMBLING_DISABLE =
+ dc_dp_initialize_scrambling_data_symbols(link, pattern);
+
dpcd_lt_buffer[DP_TRAINING_PATTERN_SET - DP_TRAINING_PATTERN_SET]
= dpcd_pattern.raw;