From patchwork Mon Feb 24 17:26:41 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ville Syrjala X-Patchwork-Id: 13988579 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6E71EC021BB for ; Mon, 24 Feb 2025 17:27:10 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DD05C10E499; Mon, 24 Feb 2025 17:27:09 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="Yn3S5gs+"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7053410E494; Mon, 24 Feb 2025 17:27:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1740418029; x=1771954029; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=loxp2Er5eT4/kkofmVW4jD3rYKVKi+wk/9DgzHKEzt0=; b=Yn3S5gs+91cxXzRj4HBVYDFX+W6HdsRQ/SFHuScUeYNzaj79lJhZ6oIo jRMfz2T/VZ+znM36ljLh2xunQLs53gLZQpbOJRqfLeT07iVx0jg415QlP VFriTL3elr7zMrOv4Y7UHXgGYOIFUGwu1kaC3UPb+NYlPPlWhzexCgvWi w76mH6ZqKD7SGb4nSCdXPAlqjOr80HUswu1C2pDPddCx7Q1t0FfP0bacz LldJPq/2Key/yI8HWBEFWL+bHE5S9RUyZ414UB7ytDBH3d0RSEA+QbFWy qhyR8ZNYZEr/L5Tgc/z2YWl5YTzn0syoCoFDAvdfwe9ZXTeMUQ9I+kgk5 A==; X-CSE-ConnectionGUID: BWDxbjcWTCyLub1K/Esq8w== X-CSE-MsgGUID: bayblnV5RhCWdGPtdBqmeA== X-IronPort-AV: E=McAfee;i="6700,10204,11355"; a="58601751" X-IronPort-AV: E=Sophos;i="6.13,312,1732608000"; d="scan'208";a="58601751" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Feb 2025 09:27:09 -0800 X-CSE-ConnectionGUID: HQ937itzRbm1NDiNQVXQGQ== X-CSE-MsgGUID: IXb8SFcKRWabLnG7Gd4i3g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,224,1728975600"; d="scan'208";a="121374149" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.74]) by orviesa005.jf.intel.com with SMTP; 24 Feb 2025 09:27:05 -0800 Received: by stinkbox (sSMTP sendmail emulation); Mon, 24 Feb 2025 19:27:03 +0200 From: Ville Syrjala To: intel-gfx@lists.freedesktop.org Cc: intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH 5/9] drm/i915/dp: Implement the POST_LT_ADJ_REQ sequence Date: Mon, 24 Feb 2025 19:26:41 +0200 Message-ID: <20250224172645.15763-6-ville.syrjala@linux.intel.com> X-Mailer: git-send-email 2.45.3 In-Reply-To: <20250224172645.15763-1-ville.syrjala@linux.intel.com> References: <20250224172645.15763-1-ville.syrjala@linux.intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Ville Syrjälä Implement the POST_LT_ADJ_REQ sequence, which should be used to further fine tune the link if TPS4 is not supported. The POST_LT_ADJ_REQ sequence will be performed after the normal link training has succeeded. Only the final hop between the last LTTPR and DPRX will perform the POST_LT_ADJ_REQ adjustment. The earlier hops will use TPS4 instead since it's mandatory for LTTPRs. start The sequence will terminate when the sink clears the "in progress" flag, the vswing/pre-emphasis values have changed six times, or the vswing/pre-emphasis values have remained unchanged for 200 ms. Signed-off-by: Ville Syrjälä --- .../drm/i915/display/intel_dp_link_training.c | 128 +++++++++++++++++- .../drm/i915/display/intel_dp_link_training.h | 2 +- drivers/gpu/drm/i915/display/intel_dp_mst.c | 2 +- 3 files changed, 128 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c index 2506996bf16d..8863fc2c44ff 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c @@ -738,11 +738,14 @@ static void intel_dp_update_downspread_ctrl(struct intel_dp *intel_dp, void intel_dp_link_training_set_bw(struct intel_dp *intel_dp, int link_bw, int rate_select, int lane_count, - bool enhanced_framing) + bool enhanced_framing, bool post_lt_adj_req) { if (enhanced_framing) lane_count |= DP_LANE_COUNT_ENHANCED_FRAME_EN; + if (post_lt_adj_req) + lane_count |= DP_POST_LT_ADJ_REQ_GRANTED; + if (link_bw) { /* DP and eDP v1.3 and earlier link bw set method. */ u8 link_config[] = { link_bw, lane_count }; @@ -764,12 +767,25 @@ void intel_dp_link_training_set_bw(struct intel_dp *intel_dp, } } +static u32 intel_dp_training_pattern(struct intel_dp *intel_dp, + const struct intel_crtc_state *crtc_state, + enum drm_dp_phy dp_phy); + +static bool intel_dp_use_post_lt_adj_req(struct intel_dp *intel_dp, + const struct intel_crtc_state *crtc_state) +{ + return intel_dp->set_idle_link_train && + drm_dp_post_lt_adj_req_supported(intel_dp->dpcd) && + intel_dp_training_pattern(intel_dp, crtc_state, DP_PHY_DPRX) != DP_TRAINING_PATTERN_4; +} + static void intel_dp_update_link_bw_set(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state, u8 link_bw, u8 rate_select) { intel_dp_link_training_set_bw(intel_dp, link_bw, rate_select, crtc_state->lane_count, - crtc_state->enhanced_framing); + crtc_state->enhanced_framing, + intel_dp_use_post_lt_adj_req(intel_dp, crtc_state)); } /* @@ -1087,6 +1103,109 @@ intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp, return channel_eq; } +static bool +intel_dp_post_lt_adj_req(struct intel_dp *intel_dp, + const struct intel_crtc_state *crtc_state) +{ + u8 link_status[DP_LINK_STATUS_SIZE]; + unsigned long deadline; + bool timeout = false; + bool success = false; + int changes = 0; + + if (!intel_dp_use_post_lt_adj_req(intel_dp, crtc_state)) + return true; + + if (drm_dp_dpcd_read_phy_link_status(&intel_dp->aux, DP_PHY_DPRX, + link_status) < 0) { + lt_err(intel_dp, DP_PHY_DPRX, "Failed to get link status\n"); + return false; + } + + deadline = jiffies + msecs_to_jiffies_timeout(200); + + for (;;) { + /* Make sure clock is still ok */ + if (!drm_dp_clock_recovery_ok(link_status, + crtc_state->lane_count)) { + intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status); + lt_dbg(intel_dp, DP_PHY_DPRX, + "Clock recovery check failed, cannot continue POST_LT_ADJ_REQ\n"); + break; + } + + if (!drm_dp_channel_eq_ok(link_status, + crtc_state->lane_count)) { + intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status); + lt_dbg(intel_dp, DP_PHY_DPRX, "Channel EQ check failed. cannot continue POST_LT_ADJ_REQ\n"); + break; + } + + if (!drm_dp_post_lt_adj_req_in_progress(link_status)) { + success = true; + intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status); + lt_dbg(intel_dp, DP_PHY_DPRX, + "POST_LT_ADJ_REQ done (%d changes). DP Training successful\n", changes); + break; + } + + if (changes == 6) { + success = true; + intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status); + lt_dbg(intel_dp, DP_PHY_DPRX, + "POST_LT_ADJ_REQ limit reached (%d changes). DP Training successful\n", changes); + break; + } + + if (timeout) { + success = true; + intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status); + lt_dbg(intel_dp, DP_PHY_DPRX, + "POST_LT_ADJ_REQ timeout reached (%d changes). DP Training successful\n", changes); + break; + } + + fsleep(5000); + + if (drm_dp_dpcd_read_phy_link_status(&intel_dp->aux, DP_PHY_DPRX, + link_status) < 0) { + lt_err(intel_dp, DP_PHY_DPRX, "Failed to get link status\n"); + break; + } + + /* Update training set as requested by target */ + if (intel_dp_get_adjust_train(intel_dp, crtc_state, DP_PHY_DPRX, link_status)) { + deadline = jiffies + msecs_to_jiffies_timeout(200); + changes++; + + if (!intel_dp_update_link_train(intel_dp, crtc_state, DP_PHY_DPRX)) { + lt_err(intel_dp, DP_PHY_DPRX, "Failed to update link training\n"); + break; + } + } else if (time_after(jiffies, deadline)) { + timeout = true; + } + } + + return success; +} + +static void intel_dp_stop_post_lt_adj_req(struct intel_dp *intel_dp, + const struct intel_crtc_state *crtc_state) +{ + u8 lane_count; + + if (!intel_dp_use_post_lt_adj_req(intel_dp, crtc_state)) + return; + + /* clear DP_POST_LT_ADJ_REQ_GRANTED */ + lane_count = crtc_state->lane_count; + if (crtc_state->enhanced_framing) + lane_count |= DP_LANE_COUNT_ENHANCED_FRAME_EN; + + drm_dp_dpcd_writeb(&intel_dp->aux, DP_LANE_COUNT_SET, lane_count); +} + static bool intel_dp_disable_dpcd_training_pattern(struct intel_dp *intel_dp, enum drm_dp_phy dp_phy) { @@ -1372,6 +1491,11 @@ intel_dp_link_train_all_phys(struct intel_dp *intel_dp, intel_dp->set_idle_link_train(intel_dp, crtc_state); } + if (ret) + ret = intel_dp_post_lt_adj_req(intel_dp, crtc_state); + + intel_dp_stop_post_lt_adj_req(intel_dp, crtc_state); + return ret; } diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.h b/drivers/gpu/drm/i915/display/intel_dp_link_training.h index 1ba22ed6db08..33dcbde6a408 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.h +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.h @@ -21,7 +21,7 @@ void intel_dp_link_training_set_mode(struct intel_dp *intel_dp, int link_rate, bool is_vrr); void intel_dp_link_training_set_bw(struct intel_dp *intel_dp, int link_bw, int rate_select, int lane_count, - bool enhanced_framing); + bool enhanced_framing, bool post_lt_adj_req); bool intel_dp_get_adjust_train(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state, diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index 167e4a70ab12..d937143ed10f 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -2109,7 +2109,7 @@ void intel_dp_mst_prepare_probe(struct intel_dp *intel_dp) intel_dp_link_training_set_mode(intel_dp, link_rate, false); intel_dp_link_training_set_bw(intel_dp, link_bw, rate_select, lane_count, - drm_dp_enhanced_frame_cap(intel_dp->dpcd)); + drm_dp_enhanced_frame_cap(intel_dp->dpcd), false); intel_mst_set_probed_link_params(intel_dp, link_rate, lane_count); }