From patchwork Tue Jul 6 17:20:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuogee Hsieh X-Patchwork-Id: 470838 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, URIBL_BLOCKED, 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 61984C07E96 for ; Tue, 6 Jul 2021 17:21:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C57461C67 for ; Tue, 6 Jul 2021 17:21:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230498AbhGFRXw (ORCPT ); Tue, 6 Jul 2021 13:23:52 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:58390 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230447AbhGFRXv (ORCPT ); Tue, 6 Jul 2021 13:23:51 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1625592072; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=ue8F0l6NTI/MSm1XwJCUi99T1LTBtuJ1aOY2Gnu2ym8=; b=Rc5bZENw/I3Ncm6UpHoRtwGm5dmFg96GEA12JO1HQFsKwwTbYq37Ohj2EzbZPntARoZPx7dy G9VYB7a5dENa37LIbmoeABzY9y9PibeAlyX86UByY+hJEmiYJvhV4AWOku/6Gr2woIZ0FUiE mbM0MWMMBCz4CUx0Lws2DD8NUog= 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-n07.prod.us-west-2.postgun.com with SMTP id 60e490f32a2a9a9761d00cf9 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 06 Jul 2021 17:20:51 GMT Sender: khsieh=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 9B52AC43143; Tue, 6 Jul 2021 17:20:51 +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 28148C43460; Tue, 6 Jul 2021 17:20:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 28148C43460 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 7/7] drm/msm/dp: retrain link when loss of symbol lock detected Date: Tue, 6 Jul 2021 10:20:20 -0700 Message-Id: <1625592020-22658-8-git-send-email-khsieh@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1625592020-22658-1-git-send-email-khsieh@codeaurora.org> References: <1625592020-22658-1-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 | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c index 0cb01a9..e616ab2 100644 --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c @@ -1661,6 +1661,25 @@ static bool dp_ctrl_any_lane_cr_lose(struct dp_ctrl_private *ctrl, return false; } +static bool dp_ctrl_loss_symbol_lock(struct dp_ctrl_private *ctrl) +{ + u8 link_status[6]; + u8 status; + int i; + int lane = ctrl->link->link_params.num_lanes; + + dp_ctrl_read_link_status(ctrl, link_status); + + for (i = 0; i < lane; 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; @@ -1777,6 +1796,17 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl) return rc; } +static int dp_ctrl_link_retrain(struct dp_ctrl_private *ctrl) +{ + int ret = 0; + u8 cr_status[2]; + int training_step = DP_TRAINING_NONE; + + ret = dp_ctrl_setup_main_link(ctrl, cr_status, &training_step); + + return ret; +} + int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl) { int ret = 0; @@ -1802,6 +1832,10 @@ int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl) } } + /* if loss symbol lock happen, then retaining the link */ + 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);