From patchwork Mon Sep 12 16:23:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuogee Hsieh X-Patchwork-Id: 12973796 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81FC2ECAAD5 for ; Mon, 12 Sep 2022 16:24:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229880AbiILQYP (ORCPT ); Mon, 12 Sep 2022 12:24:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41218 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229766AbiILQYO (ORCPT ); Mon, 12 Sep 2022 12:24:14 -0400 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B06332A72C; Mon, 12 Sep 2022 09:24:13 -0700 (PDT) Received: from pps.filterd (m0279873.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 28CGNQ3v028637; Mon, 12 Sep 2022 16:24:06 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=qcppdkim1; bh=w/wD8BcUtkpwAsqfRAeRE4enhVaNgSTfXYBMfuE5VC4=; b=gOG5/wIek3ouKhXtoYcjPVFxEa/l4gnf/vO0yNHfr7PyLZnuxHHLluxhLigqmoo1hvi1 h6UC2X3jMYEZCWZETPkeK7RnAgXuLVUt3wi3cRbG9XpyvNDI9QDBbUf8PUmwjI2NtV7d 27+2dHQPxb9gtDmiNUsdIOnx2uPJH23T3aVlO5nxQN/JzPEw4qpVE+vQjfYmnya0mnBu 4Xx21irdI+P42uiCXLXyswDxEOkQkxLBaPEUEBOAzqWDJjKPrGdbgREkiCgfpkCVcpIA +FPZIxXcf0NamajfF09WELaPwIAson8Ravpk/tZrOLd1MwJN0IhO3YoHI6C5CQNTonhi EA== Received: from nalasppmta04.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3jgk6kcj88-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 12 Sep 2022 16:24:06 +0000 Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA04.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 28CGO5lo001681 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 12 Sep 2022 16:24:05 GMT Received: from khsieh-linux1.qualcomm.com (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.29; Mon, 12 Sep 2022 09:24:04 -0700 From: Kuogee Hsieh To: , , , , , , , , , , CC: Kuogee Hsieh , , , , , Subject: [PATCH v5 1/3] drm/msm/dp: cleared DP_DOWNSPREAD_CTRL register before start link training Date: Mon, 12 Sep 2022 09:23:48 -0700 Message-ID: <1662999830-13916-2-git-send-email-quic_khsieh@quicinc.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1662999830-13916-1-git-send-email-quic_khsieh@quicinc.com> References: <1662999830-13916-1-git-send-email-quic_khsieh@quicinc.com> MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: tXiPEVog3ef2xcck1Ulho5aMzB1GUUpi X-Proofpoint-ORIG-GUID: tXiPEVog3ef2xcck1Ulho5aMzB1GUUpi X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.528,FMLib:17.11.122.1 definitions=2022-09-12_11,2022-09-12_02,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 adultscore=0 mlxscore=0 suspectscore=0 priorityscore=1501 phishscore=0 bulkscore=0 lowpriorityscore=0 clxscore=1015 impostorscore=0 spamscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2207270000 definitions=main-2209120055 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org DOWNSPREAD_CTRL (0x107) shall be cleared to 0 upon power-on reset or an upstream device disconnect. This patch will enforce this rule by always cleared DOWNSPREAD_CTRL register to 0 before start link training. At rare case that DP MSA timing parameters may be mis-interpreted by the sink which causes audio sampling rate be calculated wrongly and cause audio did not work at sink if DOWNSPREAD_CTRL register is not cleared to 0. Changes in v2: 1) fix spelling at commit text 2) merge ssc variable into encoding[0] Changes in v3: -- correct spelling of DOWNSPREAD_CTRL -- replace err with len of ssize_t Changes in v4: -- split into 2 patches Fixes: 154b5a7da0fd ("drm/msm/dp: add displayPort driver support") Signed-off-by: Kuogee Hsieh Reviewed-by: Dmitry Baryshkov --- drivers/gpu/drm/msm/dp/dp_ctrl.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c index ab6aa13..2c74c59 100644 --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c @@ -1245,8 +1245,7 @@ static int dp_ctrl_link_train(struct dp_ctrl_private *ctrl, { int ret = 0; const u8 *dpcd = ctrl->panel->dpcd; - u8 encoding = DP_SET_ANSI_8B10B; - u8 ssc; + u8 encoding[] = { 0, DP_SET_ANSI_8B10B }; u8 assr; struct dp_link_info link_info = {0}; @@ -1258,13 +1257,11 @@ static int dp_ctrl_link_train(struct dp_ctrl_private *ctrl, dp_aux_link_configure(ctrl->aux, &link_info); - if (drm_dp_max_downspread(dpcd)) { - ssc = DP_SPREAD_AMP_0_5; - drm_dp_dpcd_write(ctrl->aux, DP_DOWNSPREAD_CTRL, &ssc, 1); - } + if (drm_dp_max_downspread(dpcd)) + encoding[0] |= DP_SPREAD_AMP_0_5; - drm_dp_dpcd_write(ctrl->aux, DP_MAIN_LINK_CHANNEL_CODING_SET, - &encoding, 1); + /* config DOWNSPREAD_CTRL and MAIN_LINK_CHANNEL_CODING_SET */ + drm_dp_dpcd_write(ctrl->aux, DP_DOWNSPREAD_CTRL, encoding, 2); if (drm_dp_alternate_scrambler_reset_cap(dpcd)) { assr = DP_ALTERNATE_SCRAMBLER_RESET_ENABLE;