From patchwork Mon Nov 22 18:34:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Timo Aaltonen X-Patchwork-Id: 1558210 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4HybYH2F60z9sRN for ; Tue, 23 Nov 2021 05:35:15 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1mpE9Z-00083s-42; Mon, 22 Nov 2021 18:34:57 +0000 Received: from smtp-relay-canonical-0.internal ([10.131.114.83] helo=smtp-relay-canonical-0.canonical.com) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1mpE91-0007QQ-MO for kernel-team@lists.ubuntu.com; Mon, 22 Nov 2021 18:34:23 +0000 Received: from leon.. (mobile-user-c1d2e5-215.dhcp.inet.fi [193.210.229.215]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-canonical-0.canonical.com (Postfix) with ESMTPSA id 52FB040079 for ; Mon, 22 Nov 2021 18:34:23 +0000 (UTC) From: Timo Aaltonen To: kernel-team@lists.ubuntu.com Subject: [PATCH 12/30] drm/amd/display: Implement DPIA clock recovery phase Date: Mon, 22 Nov 2021 20:34:00 +0200 Message-Id: <20211122183418.73674-13-tjaalton@ubuntu.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211122183418.73674-1-tjaalton@ubuntu.com> References: <20211122183418.73674-1-tjaalton@ubuntu.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Jimmy Kizito BugLink: https://bugs.launchpad.net/bugs/1951868 [Why] Clock recovery is the mandatory first phase of DP link training. [How] - Implement clock recovery phase in DPIA training module. - Add helper functions for building SET_CONFIG messages. Reviewed-by: Jun Lei Acked-by: Wayne Lin Acked-by: Nicholas Kazlauskas Acked-by: Harry Wentland Signed-off-by: Jimmy Kizito Signed-off-by: Alex Deucher (cherry picked from commit 18b11f9bd4d9b51fa87a7f093b516fd6d07e74be) Signed-off-by: Timo Aaltonen --- .../drm/amd/display/dc/core/dc_link_dpia.c | 424 +++++++++++++++++- .../gpu/drm/amd/display/dc/inc/dc_link_dpia.h | 40 ++ 2 files changed, 457 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dpia.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dpia.c index 1184ff84b767..2bb78a3513f7 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dpia.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dpia.c @@ -29,6 +29,9 @@ #include "inc/core_status.h" #include "dc_link.h" #include "dc_link_dp.h" +#include "dpcd_defs.h" +#include "link_hwss.h" +#include "inc/link_dpcd.h" #define DC_LOGGER \ link->ctx->logger @@ -88,17 +91,389 @@ static enum link_training_result dpia_configure_link(struct dc_link *link, return LINK_TRAINING_SUCCESS; } +static enum dc_status core_link_send_set_config(struct dc_link *link, + uint8_t msg_type, uint8_t msg_data) +{ + /** @todo Implement */ + return DC_OK; +} + +/* Build SET_CONFIG message data payload for specified message type. */ +static uint8_t dpia_build_set_config_data(enum dpia_set_config_type type, + struct dc_link *link, + struct link_training_settings *lt_settings) +{ + union dpia_set_config_data data; + + data.raw = 0; + + switch (type) { + case DPIA_SET_CFG_SET_LINK: + data.set_link.mode = link->lttpr_mode == LTTPR_MODE_NON_TRANSPARENT ? 1 : 0; + break; + case DPIA_SET_CFG_SET_PHY_TEST_MODE: + break; + case DPIA_SET_CFG_SET_VSPE: + /* Assume all lanes have same drive settings. */ + data.set_vspe.swing = lt_settings->lane_settings[0].VOLTAGE_SWING; + data.set_vspe.pre_emph = lt_settings->lane_settings[0].PRE_EMPHASIS; + data.set_vspe.max_swing_reached = + lt_settings->lane_settings[0].VOLTAGE_SWING == + VOLTAGE_SWING_MAX_LEVEL ? 1 : 0; + data.set_vspe.max_pre_emph_reached = + lt_settings->lane_settings[0].PRE_EMPHASIS == + PRE_EMPHASIS_MAX_LEVEL ? 1 : 0; + break; + default: + ASSERT(false); /* Message type not supported by helper function. */ + break; + } + + return data.raw; +} + +/* Convert DC training pattern to DPIA training stage. */ +static enum dpia_set_config_ts convert_trng_ptn_to_trng_stg(enum dc_dp_training_pattern tps) +{ + enum dpia_set_config_ts ts; + + switch (tps) { + case DP_TRAINING_PATTERN_SEQUENCE_1: + ts = DPIA_TS_TPS1; + break; + case DP_TRAINING_PATTERN_SEQUENCE_2: + ts = DPIA_TS_TPS2; + break; + case DP_TRAINING_PATTERN_SEQUENCE_3: + ts = DPIA_TS_TPS3; + break; + case DP_TRAINING_PATTERN_SEQUENCE_4: + ts = DPIA_TS_TPS4; + break; + default: + ASSERT(false); /* TPS not supported by helper function. */ + break; + } + + return ts; +} + +/* Write training pattern to DPCD. */ +static enum dc_status dpcd_set_lt_pattern(struct dc_link *link, + enum dc_dp_training_pattern pattern, + uint32_t hop) +{ + union dpcd_training_pattern dpcd_pattern = { {0} }; + uint32_t dpcd_tps_offset = DP_TRAINING_PATTERN_SET; + enum dc_status status; + + if (hop != DPRX) + dpcd_tps_offset = DP_TRAINING_PATTERN_SET_PHY_REPEATER1 + + ((DP_REPEATER_CONFIGURATION_AND_STATUS_SIZE) * (hop - 1)); + + /* DpcdAddress_TrainingPatternSet */ + 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); + + if (hop != DPRX) { + DC_LOG_HW_LINK_TRAINING("%s\n LTTPR Repeater ID: %d\n 0x%X pattern = %x\n", + __func__, + hop, + dpcd_tps_offset, + dpcd_pattern.v1_4.TRAINING_PATTERN_SET); + } else { + DC_LOG_HW_LINK_TRAINING("%s\n 0x%X pattern = %x\n", + __func__, + dpcd_tps_offset, + dpcd_pattern.v1_4.TRAINING_PATTERN_SET); + } + + status = core_link_write_dpcd(link, + DP_TRAINING_PATTERN_SET, + &dpcd_pattern.raw, + sizeof(dpcd_pattern.raw)); + + return status; +} + +/* Execute clock recovery phase of link training for specified hop in display + * path.in non-transparent mode: + * - Driver issues both DPCD and SET_CONFIG transactions. + * - TPS1 is transmitted for any hops downstream of DPOA. + * - Drive (VS/PE) only transmitted for the hop immediately downstream of DPOA. + * - CR for the first hop (DPTX-to-DPIA) is assumed to be successful. + * + * @param link DPIA link being trained. + * @param lt_settings link_setting and drive settings (voltage swing and pre-emphasis). + * @param hop The Hop in display path. DPRX = 0. + */ +static enum link_training_result dpia_training_cr_non_transparent(struct dc_link *link, + struct link_training_settings *lt_settings, + uint32_t hop) +{ + enum link_training_result result = LINK_TRAINING_CR_FAIL_LANE0; + uint8_t repeater_cnt = 0; /* Number of hops/repeaters in display path. */ + enum dc_status status; + uint32_t retries_cr = 0; /* Number of consecutive attempts with same VS or PE. */ + uint32_t retry_count = 0; + /* From DP spec, CR read interval is always 100us. */ + uint32_t wait_time_microsec = TRAINING_AUX_RD_INTERVAL; + struct link_training_settings req_settings; + enum dc_lane_count lane_count = lt_settings->link_settings.lane_count; + union lane_status dpcd_lane_status[LANE_COUNT_DP_MAX] = { { {0} } }; + union lane_align_status_updated dpcd_lane_status_updated = { {0} }; + uint8_t set_cfg_data; + enum dpia_set_config_ts ts; + + repeater_cnt = dp_convert_to_count(link->dpcd_caps.lttpr_caps.phy_repeater_cnt); + + /* Cap of LINK_TRAINING_MAX_CR_RETRY attempts at clock recovery. + * Fix inherited from perform_clock_recovery_sequence() - + * the DP equivalent of this function: + * Required for Synaptics MST hub which can put the LT in + * infinite loop by switching the VS between level 0 and level 1 + * continuously. + */ + while ((retries_cr < LINK_TRAINING_MAX_RETRY_COUNT) && + (retry_count < LINK_TRAINING_MAX_CR_RETRY)) { + /* DPTX-to-DPIA */ + if (hop == repeater_cnt) { + /* Send SET_CONFIG(SET_LINK:LC,LR,LTTPR) to notify DPOA that + * non-transparent link training has started. + * This also enables the transmission of clk_sync packets. + */ + set_cfg_data = dpia_build_set_config_data(DPIA_SET_CFG_SET_LINK, + link, + lt_settings); + status = core_link_send_set_config(link, + DPIA_SET_CFG_SET_LINK, + set_cfg_data); + /* CR for this hop is considered successful as long as + * SET_CONFIG message is acknowledged by DPOA. + */ + if (status == DC_OK) + result = LINK_TRAINING_SUCCESS; + else + result = LINK_TRAINING_ABORT; + break; + } + + /* DPOA-to-x */ + /* Instruct DPOA to transmit TPS1 then update DPCD. */ + if (retry_count == 0) { + ts = convert_trng_ptn_to_trng_stg(lt_settings->pattern_for_cr); + status = core_link_send_set_config(link, + DPIA_SET_CFG_SET_TRAINING, + ts); + if (status != DC_OK) { + result = LINK_TRAINING_ABORT; + break; + } + status = dpcd_set_lt_pattern(link, lt_settings->pattern_for_cr, hop); + if (status != DC_OK) { + result = LINK_TRAINING_ABORT; + break; + } + } + + /* Update DPOA drive settings then DPCD. DPOA does only adjusts + * drive settings for hops immediately downstream. + */ + if (hop == repeater_cnt - 1) { + set_cfg_data = dpia_build_set_config_data(DPIA_SET_CFG_SET_VSPE, + link, + lt_settings); + status = core_link_send_set_config(link, + DPIA_SET_CFG_SET_VSPE, + set_cfg_data); + if (status != DC_OK) { + result = LINK_TRAINING_ABORT; + break; + } + } + status = dpcd_set_lane_settings(link, lt_settings, hop); + if (status != DC_OK) { + result = LINK_TRAINING_ABORT; + break; + } + + dp_wait_for_training_aux_rd_interval(link, wait_time_microsec); + + /* Read status and adjustment requests from DPCD. */ + status = dp_get_lane_status_and_drive_settings(link, + lt_settings, + dpcd_lane_status, + &dpcd_lane_status_updated, + &req_settings, + hop); + if (status != DC_OK) { + result = LINK_TRAINING_ABORT; + break; + } + + /* Check if clock recovery successful. */ + if (dp_is_cr_done(lane_count, dpcd_lane_status)) { + result = LINK_TRAINING_SUCCESS; + break; + } + + result = dp_get_cr_failure(lane_count, dpcd_lane_status); + + if (dp_is_max_vs_reached(lt_settings)) + break; + + /* Count number of attempts with same drive settings. + * Note: settings are the same for all lanes, + * so comparing first lane is sufficient. + */ + if (lt_settings->lane_settings[0].VOLTAGE_SWING == + req_settings.lane_settings[0].VOLTAGE_SWING && + lt_settings->lane_settings[0].PRE_EMPHASIS == + req_settings.lane_settings[0].PRE_EMPHASIS) + retries_cr++; + else + retries_cr = 0; + + /* Update VS/PE. */ + dp_update_drive_settings(lt_settings, req_settings); + retry_count++; + } + + /* Abort link training if clock recovery failed due to HPD unplug. */ + if (!link->hpd_status) + result = LINK_TRAINING_ABORT; + + DC_LOG_HW_LINK_TRAINING("%s\n DPIA(%d) clock recovery\n" + " -hop(%d)\n - result(%d)\n - retries(%d)\n", + __func__, + link->link_id.enum_id - ENUM_ID_1, + hop, + result, + retry_count); + + return result; +} + +/* Execute clock recovery phase of link training in transparent LTTPR mode: + * - Driver only issues DPCD transactions and leaves USB4 tunneling (SET_CONFIG) messages to DPIA. + * - Driver writes TPS1 to DPCD to kick off training. + * - Clock recovery (CR) for link is handled by DPOA, which reports result to DPIA on completion. + * - DPIA communicates result to driver by updating CR status when driver reads DPCD. + * + * @param link DPIA link being trained. + * @param lt_settings link_setting and drive settings (voltage swing and pre-emphasis). + */ +static enum link_training_result dpia_training_cr_transparent(struct dc_link *link, + struct link_training_settings *lt_settings) +{ + enum link_training_result result = LINK_TRAINING_CR_FAIL_LANE0; + enum dc_status status; + uint32_t retries_cr = 0; /* Number of consecutive attempts with same VS or PE. */ + uint32_t retry_count = 0; + uint32_t wait_time_microsec = lt_settings->cr_pattern_time; + struct link_training_settings req_settings; + enum dc_lane_count lane_count = lt_settings->link_settings.lane_count; + union lane_status dpcd_lane_status[LANE_COUNT_DP_MAX] = { { {0} } }; + union lane_align_status_updated dpcd_lane_status_updated = { {0} }; + + /* Cap of LINK_TRAINING_MAX_CR_RETRY attempts at clock recovery. + * Fix inherited from perform_clock_recovery_sequence() - + * the DP equivalent of this function: + * Required for Synaptics MST hub which can put the LT in + * infinite loop by switching the VS between level 0 and level 1 + * continuously. + */ + while ((retries_cr < LINK_TRAINING_MAX_RETRY_COUNT) && + (retry_count < LINK_TRAINING_MAX_CR_RETRY)) { + /* Write TPS1 (not VS or PE) to DPCD to start CR phase. + * DPIA sends SET_CONFIG(SET_LINK) to notify DPOA to + * start link training. + */ + if (retry_count == 0) { + status = dpcd_set_lt_pattern(link, lt_settings->pattern_for_cr, DPRX); + if (status != DC_OK) { + result = LINK_TRAINING_ABORT; + break; + } + } + + dp_wait_for_training_aux_rd_interval(link, wait_time_microsec); + + /* Read status and adjustment requests from DPCD. */ + status = dp_get_lane_status_and_drive_settings(link, + lt_settings, + dpcd_lane_status, + &dpcd_lane_status_updated, + &req_settings, + DPRX); + if (status != DC_OK) { + result = LINK_TRAINING_ABORT; + break; + } + + /* Check if clock recovery successful. */ + if (dp_is_cr_done(lane_count, dpcd_lane_status)) { + result = LINK_TRAINING_SUCCESS; + break; + } + + result = dp_get_cr_failure(lane_count, dpcd_lane_status); + + if (dp_is_max_vs_reached(lt_settings)) + break; + + /* Count number of attempts with same drive settings. + * Note: settings are the same for all lanes, + * so comparing first lane is sufficient. + */ + if (lt_settings->lane_settings[0].VOLTAGE_SWING == + req_settings.lane_settings[0].VOLTAGE_SWING && + lt_settings->lane_settings[0].PRE_EMPHASIS == + req_settings.lane_settings[0].PRE_EMPHASIS) + retries_cr++; + else + retries_cr = 0; + + /* Update VS/PE. */ + dp_update_drive_settings(lt_settings, req_settings); + retry_count++; + } + + /* Abort link training if clock recovery failed due to HPD unplug. */ + if (!link->hpd_status) + result = LINK_TRAINING_ABORT; + + DC_LOG_HW_LINK_TRAINING("%s\n DPIA(%d) clock recovery\n" + " -hop(%d)\n - result(%d)\n - retries(%d)\n", + __func__, + link->link_id.enum_id - ENUM_ID_1, + DPRX, + result, + retry_count); + + return result; +} + /* Execute clock recovery phase of link training for specified hop in display * path. + * + * @param link DPIA link being trained. + * @param lt_settings link_setting and drive settings (voltage swing and pre-emphasis). + * @param hop The Hop in display path. DPRX = 0. */ static enum link_training_result dpia_training_cr_phase(struct dc_link *link, struct link_training_settings *lt_settings, uint32_t hop) { - enum link_training_result result; + enum link_training_result result = LINK_TRAINING_CR_FAIL_LANE0; - /** @todo Fail until implemented. */ - result = LINK_TRAINING_ABORT; + if (link->lttpr_mode == LTTPR_MODE_NON_TRANSPARENT) + result = dpia_training_cr_non_transparent(link, lt_settings, hop); + else + result = dpia_training_cr_transparent(link, lt_settings); return result; } @@ -130,6 +505,38 @@ static enum link_training_result dpia_training_end(struct dc_link *link, return result; } +/* When aborting training of specified hop in display path, clean up by: + * - Attempting to clear DPCD TRAINING_PATTERN_SET, LINK_BW_SET and LANE_COUNT_SET. + * - Sending SET_CONFIG(SET_LINK) with lane count and link rate set to 0. + * + * @param link DPIA link being trained. + * @param hop The Hop in display path. DPRX = 0. + */ +static void dpia_training_abort(struct dc_link *link, uint32_t hop) +{ + uint8_t data = 0; + uint32_t dpcd_tps_offset = DP_TRAINING_PATTERN_SET; + + DC_LOG_HW_LINK_TRAINING("%s\n DPIA(%d) aborting\n - LTTPR mode(%d)\n - HPD(%d)\n", + __func__, + link->link_id.enum_id - ENUM_ID_1, + link->lttpr_mode, + link->hpd_status); + + /* Abandon clean-up if sink unplugged. */ + if (!link->hpd_status) + return; + + if (hop != DPRX) + dpcd_tps_offset = DP_TRAINING_PATTERN_SET_PHY_REPEATER1 + + ((DP_REPEATER_CONFIGURATION_AND_STATUS_SIZE) * (hop - 1)); + + core_link_write_dpcd(link, dpcd_tps_offset, &data, 1); + core_link_write_dpcd(link, DP_LINK_BW_SET, &data, 1); + core_link_write_dpcd(link, DP_LANE_COUNT_SET, &data, 1); + core_link_send_set_config(link, DPIA_SET_CFG_SET_LINK, data); +} + enum link_training_result dc_link_dpia_perform_link_training(struct dc_link *link, const struct dc_link_settings *link_setting, bool skip_video_pattern) @@ -167,14 +574,17 @@ enum link_training_result dc_link_dpia_perform_link_training(struct dc_link *lin break; } - /* Double-check link status if training successful; gracefully stop - * training of current hop if training failed for any reason other than - * sink unplug. + /* Double-check link status if training successful; gracefully abort + * training of current hop if training failed due to message tunneling + * failure; end training of hop if training ended conventionally and + * falling back to lower bandwidth settings possible. */ if (result == LINK_TRAINING_SUCCESS) { msleep(5); result = dp_check_link_loss_status(link, <_settings); - } else if (result != LINK_TRAINING_ABORT) { + } else if (result == LINK_TRAINING_ABORT) { + dpia_training_abort(link, repeater_id); + } else { dpia_training_end(link, repeater_id); } return result; diff --git a/drivers/gpu/drm/amd/display/dc/inc/dc_link_dpia.h b/drivers/gpu/drm/amd/display/dc/inc/dc_link_dpia.h index fecb07b3314d..2ea0c31326b3 100644 --- a/drivers/gpu/drm/amd/display/dc/inc/dc_link_dpia.h +++ b/drivers/gpu/drm/amd/display/dc/inc/dc_link_dpia.h @@ -32,6 +32,46 @@ struct dc_link; struct dc_link_settings; +/* The approximate time (us) it takes to transmit 9 USB4 DP clock sync packets. */ +#define DPIA_CLK_SYNC_DELAY 16000 + +/* SET_CONFIG message types sent by driver. */ +enum dpia_set_config_type { + DPIA_SET_CFG_SET_LINK = 0x01, + DPIA_SET_CFG_SET_PHY_TEST_MODE = 0x05, + DPIA_SET_CFG_SET_TRAINING = 0x18, + DPIA_SET_CFG_SET_VSPE = 0x19 +}; + +/* Training stages (TS) in SET_CONFIG(SET_TRAINING) message. */ +enum dpia_set_config_ts { + DPIA_TS_DPRX_DONE = 0x00, /* Done training DPRX. */ + DPIA_TS_TPS1 = 0x01, + DPIA_TS_TPS2 = 0x02, + DPIA_TS_TPS3 = 0x03, + DPIA_TS_TPS4 = 0x07, + DPIA_TS_UFP_DONE = 0xff /* Done training DPTX-to-DPIA hop. */ +}; + +/* SET_CONFIG message data associated with messages sent by driver. */ +union dpia_set_config_data { + struct { + uint8_t mode : 1; + uint8_t reserved : 7; + } set_link; + struct { + uint8_t stage; + } set_training; + struct { + uint8_t swing : 2; + uint8_t max_swing_reached : 1; + uint8_t pre_emph : 2; + uint8_t max_pre_emph_reached : 1; + uint8_t reserved : 2; + } set_vspe; + uint8_t raw; +}; + /* Read tunneling device capability from DPCD and update link capability * accordingly. */