From 81bb9bc95355055e2fa297b9a81e9d786eca9903 Mon Sep 17 00:00:00 2001 From: George Shen Date: Sat, 20 Nov 2021 18:35:15 -0500 Subject: [PATCH] drm/amd/display: Add W/A for PHY tests with certain LTTPR [Why] Certain LTTPR require output VS/PE to be explicitly set during PHY test automation. [How] Add vendor-specific sequence to set LTTPR output VS/PE. Reviewed-by: Jun Lei Acked-by: Pavle Kotarac Signed-off-by: George Shen Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 72 +++++++++++++++++++++++- 1 file changed, 70 insertions(+), 2 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 574a66833387..0534f17e3676 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 @@ -515,6 +515,21 @@ static void vendor_specific_lttpr_wa_three( } } +static void vendor_specific_lttpr_wa_three_dpcd( + struct dc_link *link, + union dpcd_training_lane dpcd_lane_adjust[LANE_COUNT_DP_MAX]) +{ + union lane_adjust lane_adjust[LANE_COUNT_DP_MAX]; + uint8_t lane = 0; + + vendor_specific_lttpr_wa_three(link, lane_adjust); + + for (lane = 0; lane < LANE_COUNT_DP_MAX; lane++) { + dpcd_lane_adjust[lane].bits.VOLTAGE_SWING_SET = lane_adjust[lane].bits.VOLTAGE_SWING_LANE; + dpcd_lane_adjust[lane].bits.PRE_EMPHASIS_SET = lane_adjust[lane].bits.PRE_EMPHASIS_LANE; + } +} + static void vendor_specific_lttpr_wa_four( struct dc_link *link, bool apply_wa) @@ -564,6 +579,42 @@ static void vendor_specific_lttpr_wa_four( #endif } +static void vendor_specific_lttpr_wa_five( + struct dc_link *link, + const union dpcd_training_lane dpcd_lane_adjust[LANE_COUNT_DP_MAX], + uint8_t lane_count) +{ + const uint32_t vendor_lttpr_write_address = 0xF004F; + const uint8_t vendor_lttpr_write_data_reset[4] = {0x1, 0x50, 0x63, 0xFF}; + uint8_t vendor_lttpr_write_data_vs[4] = {0x1, 0x51, 0x63, 0x0}; + uint8_t vendor_lttpr_write_data_pe[4] = {0x1, 0x52, 0x63, 0x0}; + uint8_t lane = 0; + + for (lane = 0; lane < lane_count; lane++) { + vendor_lttpr_write_data_vs[3] |= + dpcd_lane_adjust[lane].bits.VOLTAGE_SWING_SET << (2 * lane); + vendor_lttpr_write_data_pe[3] |= + dpcd_lane_adjust[lane].bits.PRE_EMPHASIS_SET << (2 * lane); + } + + /* Force LTTPR to output desired VS and PE */ + core_link_write_dpcd( + link, + vendor_lttpr_write_address, + &vendor_lttpr_write_data_reset[0], + sizeof(vendor_lttpr_write_data_reset)); + core_link_write_dpcd( + link, + vendor_lttpr_write_address, + &vendor_lttpr_write_data_vs[0], + sizeof(vendor_lttpr_write_data_vs)); + core_link_write_dpcd( + link, + vendor_lttpr_write_address, + &vendor_lttpr_write_data_pe[0], + sizeof(vendor_lttpr_write_data_pe)); +} + enum dc_status dpcd_set_link_settings( struct dc_link *link, const struct link_training_settings *lt_settings) @@ -3903,6 +3954,13 @@ static void dp_test_send_phy_test_pattern(struct dc_link *link) &dpcd_lane_adjustment[0].raw, sizeof(dpcd_lane_adjustment)); + if (link->dc->debug.apply_vendor_specific_lttpr_wa && + (link->chip_caps & EXT_DISPLAY_PATH_CAPS__DP_FIXED_VS_EN) && + link->lttpr_mode == LTTPR_MODE_TRANSPARENT) + vendor_specific_lttpr_wa_three_dpcd( + link, + link_training_settings.dpcd_lane_settings); + /*get post cursor 2 parameters * For DP 1.1a or eariler, this DPCD register's value is 0 * For DP 1.2 or later: @@ -5680,8 +5738,18 @@ bool dc_link_dp_set_test_pattern( if (is_dp_phy_pattern(test_pattern)) { /* Set DPCD Lane Settings before running test pattern */ if (p_link_settings != NULL) { - dp_set_hw_lane_settings(link, p_link_settings, DPRX); - dpcd_set_lane_settings(link, p_link_settings, DPRX); + if (link->dc->debug.apply_vendor_specific_lttpr_wa && + (link->chip_caps & EXT_DISPLAY_PATH_CAPS__DP_FIXED_VS_EN) && + link->lttpr_mode == LTTPR_MODE_TRANSPARENT) { + dpcd_set_lane_settings(link, p_link_settings, DPRX); + vendor_specific_lttpr_wa_five( + link, + p_link_settings->dpcd_lane_settings, + p_link_settings->link_settings.lane_count); + } else { + dp_set_hw_lane_settings(link, p_link_settings, DPRX); + dpcd_set_lane_settings(link, p_link_settings, DPRX); + } } /* Blank stream if running test pattern */ -- 2.11.0