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: 12374381 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 0ED7FC07E95 for ; Tue, 13 Jul 2021 15:55:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDAA461040 for ; Tue, 13 Jul 2021 15:55:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237194AbhGMP5u (ORCPT ); Tue, 13 Jul 2021 11:57:50 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:55813 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237214AbhGMP5t (ORCPT ); Tue, 13 Jul 2021 11:57:49 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1626191700; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=cyXJ9mJ8LBWXjwGWfk54YTCR6FHccnLnwAEVHScm1GQ=; b=QpGRyZ5sEJHzq/bIbGZSLCfC/+wg/byvmKX0P/bPAfgNhcXGlP5+Mzv6hlw57e1PHuWlTqHa VpgY+3sYR2QoF5CGUf+NYB3CJwex+kUGpdiod2JVaipXjdgIGSicZ1d10h2vUuuB1aAvSbRk JADQkbG4NJHFRZreu0xGKpk2QqQ= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n05.prod.us-west-2.postgun.com with SMTP id 60edb7535d0d101e3816383e (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 13 Jul 2021 15:54:59 GMT Sender: khsieh=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 58DD7C43460; Tue, 13 Jul 2021 15:54:59 +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 Cc: Kuogee Hsieh , abhinavk@codeaurora.org, aravindh@codeaurora.org, airlied@linux.ie, daniel@ffwll.ch, bjorn.andersson@linaro.org, linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.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> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org 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);