From patchwork Tue Jul 13 15:54:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuogee Hsieh X-Patchwork-Id: 12374403 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F0A98C07E95 for ; Tue, 13 Jul 2021 15:55:22 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id C069A61040 for ; Tue, 13 Jul 2021 15:55:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C069A61040 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4EB706E0EC; Tue, 13 Jul 2021 15:55:22 +0000 (UTC) Received: from so254-9.mailgun.net (so254-9.mailgun.net [198.61.254.9]) by gabe.freedesktop.org (Postfix) with ESMTPS id 120786E0EE for ; Tue, 13 Jul 2021 15:55:18 +0000 (UTC) DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1626191721; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=cyXJ9mJ8LBWXjwGWfk54YTCR6FHccnLnwAEVHScm1GQ=; b=VRPRjMVbjlxVXGgK+Hw2uYpYMsZPmPzid06hqhFQcUowrjdjfjPfrMarRoYUBqGS5XB2OJHx NUBoJ1S6P/QGi8d/Mt+JEC7fO2mFgS/7zh15FpbkW04T9uc5PS9nQNZgcOrnKkUA6vLx641x 1QPeuaIqqOSf48wObUHrb2y6hGo= X-Mailgun-Sending-Ip: 198.61.254.9 X-Mailgun-Sid: WyJkOTU5ZSIsICJkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n02.prod.us-east-1.postgun.com with SMTP id 60edb7555e3e57240b8f172b (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 13 Jul 2021 15:55:01 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 336D2C43149; Tue, 13 Jul 2021 15:55:00 +0000 (UTC) Received: from khsieh-linux1.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: khsieh) by smtp.codeaurora.org (Postfix) with ESMTPSA id 3E9EEC43152; Tue, 13 Jul 2021 15:54:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 3E9EEC43152 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=khsieh@codeaurora.org From: Kuogee Hsieh To: dri-devel@lists.freedesktop.org, robdclark@gmail.com, sean@poorly.run, swboyd@chromium.org Subject: [PATCH v2 7/7] drm/msm/dp: retrain link when loss of symbol lock detected Date: Tue, 13 Jul 2021 08:54:07 -0700 Message-Id: <1626191647-13901-8-git-send-email-khsieh@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1626191647-13901-1-git-send-email-khsieh@codeaurora.org> References: <1626191647-13901-1-git-send-email-khsieh@codeaurora.org> 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: , Cc: airlied@linux.ie, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, abhinavk@codeaurora.org, bjorn.andersson@linaro.org, Kuogee Hsieh , aravindh@codeaurora.org, freedreno@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Main link symbol locked is achieved at end of link training 2. Some dongle main link symbol may become unlocked again if host did not end link training soon enough after completion of link training 2. Host have to re train main link if loss of symbol lock detected before end link training so that the coming video stream can be transmitted to sink properly. Signed-off-by: Kuogee Hsieh --- drivers/gpu/drm/msm/dp/dp_ctrl.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c index 6a013b0..20951c8 100644 --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c @@ -1638,6 +1638,25 @@ static bool dp_ctrl_clock_recovery_any_ok( return drm_dp_clock_recovery_ok(link_status, lane_count); } +static bool dp_ctrl_loss_symbol_lock(struct dp_ctrl_private *ctrl) +{ + u8 link_status[DP_LINK_STATUS_SIZE]; + u8 status; + int i; + int num_lanes = ctrl->link->link_params.num_lanes; + + dp_ctrl_read_link_status(ctrl, link_status); + + for (i = 0; i < num_lanes; i++) { + status = link_status[i / 2]; + status >>= ((i % 2) * 4); + if (!(status & DP_LANE_SYMBOL_LOCKED)) + return true; + } + + return false; +} + int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl) { int rc = 0; @@ -1761,6 +1780,13 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl) return rc; } +static int dp_ctrl_link_retrain(struct dp_ctrl_private *ctrl) +{ + int training_step = DP_TRAINING_NONE; + + return dp_ctrl_setup_main_link(ctrl, &training_step); +} + int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl) { int ret = 0; @@ -1786,6 +1812,9 @@ int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl) } } + if (dp_ctrl_loss_symbol_lock(ctrl)) + dp_ctrl_link_retrain(ctrl); + /* stop txing train pattern to end link training */ dp_ctrl_clear_training_pattern(ctrl);