From patchwork Mon Nov 22 18:33:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Timo Aaltonen X-Patchwork-Id: 1558209 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 4HybY94qrQz9sRN for ; Tue, 23 Nov 2021 05:35:09 +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 1mpE9V-0007zc-Vf; Mon, 22 Nov 2021 18:34:54 +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 1mpE90-0007Pn-W2 for kernel-team@lists.ubuntu.com; Mon, 22 Nov 2021 18:34:22 +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 AAA444007C for ; Mon, 22 Nov 2021 18:34:22 +0000 (UTC) From: Timo Aaltonen To: kernel-team@lists.ubuntu.com Subject: [PATCH 10/30] drm/amd/display: Implement DPIA training loop Date: Mon, 22 Nov 2021 20:33:58 +0200 Message-Id: <20211122183418.73674-11-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] Training of DPIA link differs enough from that of conventional DP link to warrant a separate implementation. [How] - Implement top-level of DPIA training loop. - Make functions shared between DP and DPIA link training "public". 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 178fbb6d552f294037291bf62d41b31d30186f31) Signed-off-by: Timo Aaltonen --- .../gpu/drm/amd/display/dc/core/dc_link_dp.c | 17 --- .../drm/amd/display/dc/core/dc_link_dpia.c | 109 ++++++++++++++++++ .../gpu/drm/amd/display/dc/inc/dc_link_dpia.h | 10 ++ drivers/gpu/drm/amd/display/dc/os_types.h | 1 + 4 files changed, 120 insertions(+), 17 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 b535b30b4560..02ecdb4b196f 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 @@ -1776,23 +1776,6 @@ enum link_training_result dc_link_dp_perform_link_training( return status; } -/* - * Train DP tunneling link for USB4 DPIA display endpoint. - * - * DPIA equivalent of dc_link_dp_perfrorm_link_training. - */ -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) -{ - enum link_training_result status; - - /** @todo Always fail until USB4 DPIA training implemented. */ - status = LINK_TRAINING_CR_FAIL_LANE0; - - return status; -} - bool perform_link_training_with_retries( const struct dc_link_settings *link_setting, bool skip_video_pattern, 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 f11dc9e28d3f..afb18cba3efa 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 @@ -24,12 +24,121 @@ * */ +#include "dc.h" #include "dc_link_dpia.h" #include "inc/core_status.h" #include "dc_link.h" +#include "dc_link_dp.h" enum dc_status dpcd_get_tunneling_device_data(struct dc_link *link) { /** @todo Read corresponding DPCD region and update link caps. */ return DC_OK; } + +/* Configure link as prescribed in link_setting; set LTTPR mode; and + * Initialize link training settings. + */ +static enum link_training_result dpia_configure_link(struct dc_link *link, + const struct dc_link_settings *link_setting, + struct link_training_settings *lt_settings) +{ + enum link_training_result result; + + /** @todo Fail until implemented. */ + result = LINK_TRAINING_ABORT; + + return result; +} + +/* Execute clock recovery phase of link training for specified hop in display + * path. + */ +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; + + /** @todo Fail until implemented. */ + result = LINK_TRAINING_ABORT; + + return result; +} + +/* Execute equalization phase of link training for specified hop in display + * path. + */ +static enum link_training_result dpia_training_eq_phase(struct dc_link *link, + struct link_training_settings *lt_settings, + uint32_t hop) +{ + enum link_training_result result; + + /** @todo Fail until implemented. */ + result = LINK_TRAINING_ABORT; + + return result; +} + +/* End training of specified hop in display path. */ +static enum link_training_result dpia_training_end(struct dc_link *link, + uint32_t hop) +{ + enum link_training_result result; + + /** @todo Fail until implemented. */ + result = LINK_TRAINING_ABORT; + + return result; +} + +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) +{ + enum link_training_result result; + struct link_training_settings lt_settings; + uint8_t repeater_cnt = 0; /* Number of hops/repeaters in display path. */ + uint8_t repeater_id; /* Current hop. */ + + /* Configure link as prescribed in link_setting and set LTTPR mode. */ + result = dpia_configure_link(link, link_setting, <_settings); + if (result != LINK_TRAINING_SUCCESS) + return result; + + if (link->lttpr_mode == LTTPR_MODE_NON_TRANSPARENT) + repeater_cnt = dp_convert_to_count(link->dpcd_caps.lttpr_caps.phy_repeater_cnt); + + /* Train each hop in turn starting with the one closest to DPTX. + * In transparent or non-LTTPR mode, train only the final hop (DPRX). + */ + for (repeater_id = repeater_cnt; repeater_id >= 0; repeater_id--) { + /* Clock recovery. */ + result = dpia_training_cr_phase(link, <_settings, repeater_id); + if (result != LINK_TRAINING_SUCCESS) + break; + + /* Equalization. */ + result = dpia_training_eq_phase(link, <_settings, repeater_id); + if (result != LINK_TRAINING_SUCCESS) + break; + + /* Stop training hop. */ + result = dpia_training_end(link, repeater_id); + if (result != LINK_TRAINING_SUCCESS) + break; + } + + /* Double-check link status if training successful; gracefully stop + * training of current hop if training failed for any reason other than + * sink unplug. + */ + if (result == LINK_TRAINING_SUCCESS) { + msleep(5); + result = dp_check_link_loss_status(link, <_settings); + } else if (result != LINK_TRAINING_ABORT) { + 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 0047058cf699..fecb07b3314d 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 @@ -30,10 +30,20 @@ /* This module implements functionality for training DPIA links. */ struct dc_link; +struct dc_link_settings; /* Read tunneling device capability from DPCD and update link capability * accordingly. */ enum dc_status dpcd_get_tunneling_device_data(struct dc_link *link); +/* Train DP tunneling link for USB4 DPIA display endpoint. + * DPIA equivalent of dc_link_dp_perfrorm_link_training. + * Aborts link training upon detection of sink unplug. + */ +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); + #endif /* __DC_LINK_DPIA_H__ */ diff --git a/drivers/gpu/drm/amd/display/dc/os_types.h b/drivers/gpu/drm/amd/display/dc/os_types.h index f50cae252de4..415b56223bcf 100644 --- a/drivers/gpu/drm/amd/display/dc/os_types.h +++ b/drivers/gpu/drm/amd/display/dc/os_types.h @@ -31,6 +31,7 @@ #include #include #include +#include #include