From: Josip Pavic Date: Wed, 6 Feb 2019 00:27:38 +0000 (-0500) Subject: drm/amd/display: optionally optimize edp link rate based on timing X-Git-Tag: v5.15~6416^2~31^2~383 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=8628d02f60d4a568d02fc12a26273a55f7718ec0;p=mirror_ubuntu-kernels.git drm/amd/display: optionally optimize edp link rate based on timing [Why] eDP v1.4 allows panels to report link rates other than RBR/HBR/HBR2, that may be more optimal for the panel's timing. Power can be saved by using a link rate closer to the required bandwidth of the panel's timing. [How] Scan the table of reported link rates from the panel, and select the minimum link rate that satisfies the bandwidth requirements of the panel's timing. Include a flag to make the feature optional. Signed-off-by: Josip Pavic Reviewed-by: Harry Wentland Acked-by: Anthony Koo Acked-by: Leo Li Signed-off-by: Alex Deucher --- 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 09d301216076..8ad79df56bf8 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 @@ -93,12 +93,10 @@ static void dpcd_set_link_settings( struct dc_link *link, const struct link_training_settings *lt_settings) { - uint8_t rate = (uint8_t) - (lt_settings->link_settings.link_rate); + uint8_t rate; union down_spread_ctrl downspread = { {0} }; union lane_count_set lane_count_set = { {0} }; - uint8_t link_set_buffer[2]; downspread.raw = (uint8_t) (lt_settings->link_settings.link_spread); @@ -111,29 +109,42 @@ static void dpcd_set_link_settings( lane_count_set.bits.POST_LT_ADJ_REQ_GRANTED = link->dpcd_caps.max_ln_count.bits.POST_LT_ADJ_REQ_SUPPORTED; - link_set_buffer[0] = rate; - link_set_buffer[1] = lane_count_set.raw; - - core_link_write_dpcd(link, DP_LINK_BW_SET, - link_set_buffer, 2); core_link_write_dpcd(link, DP_DOWNSPREAD_CTRL, &downspread.raw, sizeof(downspread)); + core_link_write_dpcd(link, DP_LANE_COUNT_SET, + &lane_count_set.raw, 1); + if (link->dpcd_caps.dpcd_rev.raw >= DPCD_REV_14 && - (link->dpcd_caps.link_rate_set >= 1 && - link->dpcd_caps.link_rate_set <= 8)) { + lt_settings->link_settings.use_link_rate_set == true) { + rate = 0; + core_link_write_dpcd(link, DP_LINK_BW_SET, &rate, 1); core_link_write_dpcd(link, DP_LINK_RATE_SET, - &link->dpcd_caps.link_rate_set, 1); + <_settings->link_settings.link_rate_set, 1); + } else { + rate = (uint8_t) (lt_settings->link_settings.link_rate); + core_link_write_dpcd(link, DP_LINK_BW_SET, &rate, 1); } - DC_LOG_HW_LINK_TRAINING("%s\n %x rate = %x\n %x lane = %x\n %x spread = %x\n", - __func__, - DP_LINK_BW_SET, - lt_settings->link_settings.link_rate, - DP_LANE_COUNT_SET, - lt_settings->link_settings.lane_count, - DP_DOWNSPREAD_CTRL, - lt_settings->link_settings.link_spread); + if (rate) { + DC_LOG_HW_LINK_TRAINING("%s\n %x rate = %x\n %x lane = %x\n %x spread = %x\n", + __func__, + DP_LINK_BW_SET, + lt_settings->link_settings.link_rate, + DP_LANE_COUNT_SET, + lt_settings->link_settings.lane_count, + DP_DOWNSPREAD_CTRL, + lt_settings->link_settings.link_spread); + } else { + DC_LOG_HW_LINK_TRAINING("%s\n %x rate set = %x\n %x lane = %x\n %x spread = %x\n", + __func__, + DP_LINK_RATE_SET, + lt_settings->link_settings.link_rate_set, + DP_LANE_COUNT_SET, + lt_settings->link_settings.lane_count, + DP_DOWNSPREAD_CTRL, + lt_settings->link_settings.link_spread); + } } @@ -952,6 +963,8 @@ enum link_training_result dc_link_dp_perform_link_training( lt_settings.link_settings.link_rate = link_setting->link_rate; lt_settings.link_settings.lane_count = link_setting->lane_count; + lt_settings.link_settings.use_link_rate_set = link_setting->use_link_rate_set; + lt_settings.link_settings.link_rate_set = link_setting->link_rate_set; /*@todo[vdevulap] move SS to LS, should not be handled by displaypath*/ @@ -1075,7 +1088,7 @@ static struct dc_link_settings get_max_link_cap(struct dc_link *link) { /* Set Default link settings */ struct dc_link_settings max_link_cap = {LANE_COUNT_FOUR, LINK_RATE_HIGH, - LINK_SPREAD_05_DOWNSPREAD_30KHZ}; + LINK_SPREAD_05_DOWNSPREAD_30KHZ, false, 0}; /* Higher link settings based on feature supported */ if (link->link_enc->features.flags.bits.IS_HBR2_CAPABLE) @@ -1629,47 +1642,65 @@ bool dp_validate_mode_timing( return false; } -void decide_link_settings(struct dc_stream_state *stream, - struct dc_link_settings *link_setting) +static bool decide_dp_link_settings(struct dc_link *link, struct dc_link_settings *link_setting, uint32_t req_bw) { - struct dc_link_settings initial_link_setting = { - LANE_COUNT_ONE, LINK_RATE_LOW, LINK_SPREAD_DISABLED}; + LANE_COUNT_ONE, LINK_RATE_LOW, LINK_SPREAD_DISABLED, false, 0}; struct dc_link_settings current_link_setting = initial_link_setting; - struct dc_link *link; - uint32_t req_bw; uint32_t link_bw; - req_bw = bandwidth_in_kbps_from_timing(&stream->timing); - - link = stream->link; - - /* if preferred is specified through AMDDP, use it, if it's enough - * to drive the mode + /* search for the minimum link setting that: + * 1. is supported according to the link training result + * 2. could support the b/w requested by the timing */ - if (link->preferred_link_setting.lane_count != - LANE_COUNT_UNKNOWN && - link->preferred_link_setting.link_rate != - LINK_RATE_UNKNOWN) { - *link_setting = link->preferred_link_setting; - return; - } + while (current_link_setting.link_rate <= + link->verified_link_cap.link_rate) { + link_bw = bandwidth_in_kbps_from_link_settings( + ¤t_link_setting); + if (req_bw <= link_bw) { + *link_setting = current_link_setting; + return true; + } - /* MST doesn't perform link training for now - * TODO: add MST specific link training routine - */ - if (stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST) { - *link_setting = link->verified_link_cap; - return; + if (current_link_setting.lane_count < + link->verified_link_cap.lane_count) { + current_link_setting.lane_count = + increase_lane_count( + current_link_setting.lane_count); + } else { + current_link_setting.link_rate = + increase_link_rate( + current_link_setting.link_rate); + current_link_setting.lane_count = + initial_link_setting.lane_count; + } } - /* EDP use the link cap setting */ - if (link->connector_signal == SIGNAL_TYPE_EDP) { + return false; +} + +static bool decide_edp_link_settings(struct dc_link *link, struct dc_link_settings *link_setting, uint32_t req_bw) +{ + struct dc_link_settings initial_link_setting; + struct dc_link_settings current_link_setting; + uint32_t link_bw; + + if (link->dpcd_caps.dpcd_rev.raw < DPCD_REV_14 || + link->dpcd_caps.edp_supported_link_rates_count == 0 || + link->dc->config.optimize_edp_link_rate == false) { *link_setting = link->verified_link_cap; - return; + return true; } + memset(&initial_link_setting, 0, sizeof(initial_link_setting)); + initial_link_setting.lane_count = LANE_COUNT_ONE; + initial_link_setting.link_rate = link->dpcd_caps.edp_supported_link_rates[0]; + initial_link_setting.link_spread = LINK_SPREAD_DISABLED; + initial_link_setting.use_link_rate_set = true; + initial_link_setting.link_rate_set = 0; + current_link_setting = initial_link_setting; + /* search for the minimum link setting that: * 1. is supported according to the link training result * 2. could support the b/w requested by the timing @@ -1680,7 +1711,7 @@ void decide_link_settings(struct dc_stream_state *stream, ¤t_link_setting); if (req_bw <= link_bw) { *link_setting = current_link_setting; - return; + return true; } if (current_link_setting.lane_count < @@ -1689,13 +1720,53 @@ void decide_link_settings(struct dc_stream_state *stream, increase_lane_count( current_link_setting.lane_count); } else { - current_link_setting.link_rate = - increase_link_rate( - current_link_setting.link_rate); - current_link_setting.lane_count = - initial_link_setting.lane_count; + if (current_link_setting.link_rate_set < link->dpcd_caps.edp_supported_link_rates_count) { + current_link_setting.link_rate_set++; + current_link_setting.link_rate = + link->dpcd_caps.edp_supported_link_rates[current_link_setting.link_rate_set]; + current_link_setting.lane_count = + initial_link_setting.lane_count; + } else + break; } } + return false; +} + +void decide_link_settings(struct dc_stream_state *stream, + struct dc_link_settings *link_setting) +{ + struct dc_link *link; + uint32_t req_bw; + + req_bw = bandwidth_in_kbps_from_timing(&stream->timing); + + link = stream->link; + + /* if preferred is specified through AMDDP, use it, if it's enough + * to drive the mode + */ + if (link->preferred_link_setting.lane_count != + LANE_COUNT_UNKNOWN && + link->preferred_link_setting.link_rate != + LINK_RATE_UNKNOWN) { + *link_setting = link->preferred_link_setting; + return; + } + + /* MST doesn't perform link training for now + * TODO: add MST specific link training routine + */ + if (stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST) { + *link_setting = link->verified_link_cap; + return; + } + + if (link->connector_signal == SIGNAL_TYPE_EDP) { + if (decide_edp_link_settings(link, link_setting, req_bw)) + return; + } else if (decide_dp_link_settings(link, link_setting, req_bw)) + return; BREAK_TO_DEBUGGER(); ASSERT(link->verified_link_cap.lane_count != LANE_COUNT_UNKNOWN); @@ -2536,31 +2607,31 @@ enum dc_link_rate linkRateInKHzToLinkRateMultiplier(uint32_t link_rate_in_khz) void detect_edp_sink_caps(struct dc_link *link) { - uint8_t supported_link_rates[16] = {0}; + uint8_t supported_link_rates[16]; uint32_t entry; uint32_t link_rate_in_khz; enum dc_link_rate link_rate = LINK_RATE_UNKNOWN; retrieve_link_cap(link); + link->dpcd_caps.edp_supported_link_rates_count = 0; + memset(supported_link_rates, 0, sizeof(supported_link_rates)); - if (link->dpcd_caps.dpcd_rev.raw >= DPCD_REV_14) { + if (link->dpcd_caps.dpcd_rev.raw >= DPCD_REV_14 && + link->dc->config.optimize_edp_link_rate) { // Read DPCD 00010h - 0001Fh 16 bytes at one shot core_link_read_dpcd(link, DP_SUPPORTED_LINK_RATES, supported_link_rates, sizeof(supported_link_rates)); - link->dpcd_caps.link_rate_set = 0; for (entry = 0; entry < 16; entry += 2) { // DPCD register reports per-lane link rate = 16-bit link rate capability - // value X 200 kHz. Need multipler to find link rate in kHz. + // value X 200 kHz. Need multiplier to find link rate in kHz. link_rate_in_khz = (supported_link_rates[entry+1] * 0x100 + supported_link_rates[entry]) * 200; if (link_rate_in_khz != 0) { link_rate = linkRateInKHzToLinkRateMultiplier(link_rate_in_khz); - if (link->reported_link_cap.link_rate < link_rate) { - link->reported_link_cap.link_rate = link_rate; - link->dpcd_caps.link_rate_set = entry; - } + link->dpcd_caps.edp_supported_link_rates[link->dpcd_caps.edp_supported_link_rates_count] = link_rate; + link->dpcd_caps.edp_supported_link_rates_count++; } } } diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h index a4d3da849a72..e98e19ca9c1c 100644 --- a/drivers/gpu/drm/amd/display/dc/dc.h +++ b/drivers/gpu/drm/amd/display/dc/dc.h @@ -164,6 +164,7 @@ struct dc_config { bool gpu_vm_support; bool disable_disp_pll_sharing; bool fbc_support; + bool optimize_edp_link_rate; }; enum visual_confirm { @@ -648,6 +649,10 @@ struct dpcd_caps { union max_lane_count max_ln_count; union max_down_spread max_down_spread; + /* valid only for eDP v1.4 or higher*/ + uint8_t edp_supported_link_rates_count; + enum dc_link_rate edp_supported_link_rates[8]; + /* dongle type (DP converter, CV smart dongle) */ enum display_dongle_type dongle_type; /* Dongle's downstream count. */ @@ -665,7 +670,6 @@ struct dpcd_caps { int8_t branch_dev_name[6]; int8_t branch_hw_revision; int8_t branch_fw_revision[2]; - uint8_t link_rate_set; bool allow_invalid_MSA_timing_param; bool panel_mode_edp; diff --git a/drivers/gpu/drm/amd/display/dc/dc_dp_types.h b/drivers/gpu/drm/amd/display/dc/dc_dp_types.h index d4eab33c453b..ec403cd8b834 100644 --- a/drivers/gpu/drm/amd/display/dc/dc_dp_types.h +++ b/drivers/gpu/drm/amd/display/dc/dc_dp_types.h @@ -94,6 +94,8 @@ struct dc_link_settings { enum dc_lane_count lane_count; enum dc_link_rate link_rate; enum dc_link_spread link_spread; + bool use_link_rate_set; + uint8_t link_rate_set; }; struct dc_lane_settings {