From mboxrd@z Thu Jan 1 00:00:00 1970 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 A1FE0C00140 for ; Wed, 10 Aug 2022 23:58:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233640AbiHJX6K (ORCPT ); Wed, 10 Aug 2022 19:58:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49744 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233679AbiHJX6D (ORCPT ); Wed, 10 Aug 2022 19:58:03 -0400 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8B82753AA; Wed, 10 Aug 2022 16:58:02 -0700 (PDT) Received: from pps.filterd (m0279872.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 27ANS5tu011894; Wed, 10 Aug 2022 23:57:55 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=qcppdkim1; bh=iKZo6L4ks80dAbx5RILErWCqMWwJ78yCTiIRsqpNI0w=; b=a/qivNS2b8zA43RXF6HBTCF/jVYSzkRkg+d2y7+7tsPJeGGq6anGUv7nsAt2qIsAdisn MlHPD8f2HEB7ArCltDIxY5DBxcn4L7V+2bXjwocXQdyDpeiQ47B8fwrUUh42Ei3RVh9G K0754OTB2Vb0u7c0L9w6umCQXkGNEvsCm0mJGljnQjyoDL7VGNgbkbz3w5qUq2xz30z7 /QDfZSSUSgsc8NK9fvWCDqCmveFcchZ3Eqxp+yFE1MojzMy+m0kxjx/4ICrs1qMCELVM KGS1/jAQ9SL+Y8lH6ZqEATrAgl6BS6jjqHTYsu/Z+sAv0I4H8HAgfy/dLJOxqLVUuMBM +Q== Received: from nasanppmta05.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3huwr24b0u-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 10 Aug 2022 23:57:55 +0000 Received: from nasanex01c.na.qualcomm.com (nasanex01c.na.qualcomm.com [10.47.97.222]) by NASANPPMTA05.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 27ANvrtF004901 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 10 Aug 2022 23:57:53 GMT Received: from nalasex01a.na.qualcomm.com (10.47.209.196) by nasanex01c.na.qualcomm.com (10.47.97.222) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.22; Wed, 10 Aug 2022 16:57:53 -0700 Received: from [10.110.86.199] (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 15.2.986.22; Wed, 10 Aug 2022 16:57:51 -0700 Message-ID: Date: Wed, 10 Aug 2022 16:57:51 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH v3] drm/msm/dp: check hpd_state before push idle pattern at dp_bridge_disable() Content-Language: en-US To: Stephen Boyd , , , , , , , , , CC: , , , , , , References: <1660159551-13828-1-git-send-email-quic_khsieh@quicinc.com> From: Kuogee Hsieh In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit 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: z5McM-bdfMc4yNFQcm4ab-8hgVxndqT7 X-Proofpoint-ORIG-GUID: z5McM-bdfMc4yNFQcm4ab-8hgVxndqT7 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-08-10_16,2022-08-10_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 bulkscore=0 mlxscore=0 adultscore=0 mlxlogscore=999 spamscore=0 lowpriorityscore=0 impostorscore=0 phishscore=0 clxscore=1015 priorityscore=1501 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2207270000 definitions=main-2208100072 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/10/2022 3:22 PM, Stephen Boyd wrote: > Quoting Kuogee Hsieh (2022-08-10 12:25:51) >> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c >> index b36f8b6..678289a 100644 >> --- a/drivers/gpu/drm/msm/dp/dp_display.c >> +++ b/drivers/gpu/drm/msm/dp/dp_display.c >> @@ -1729,10 +1729,20 @@ void dp_bridge_disable(struct drm_bridge *drm_bridge) >> struct msm_dp_bridge *dp_bridge = to_dp_bridge(drm_bridge); >> struct msm_dp *dp = dp_bridge->dp_display; >> struct dp_display_private *dp_display; >> + u32 state; >> >> dp_display = container_of(dp, struct dp_display_private, dp_display); >> >> + mutex_lock(&dp_display->event_mutex); >> + >> + state = dp_display->hpd_state; >> + if (state != ST_DISCONNECT_PENDING && state != ST_CONNECTED) { > It's concerning that we have to check this at all. Are we still > interjecting into the disable path when the cable is disconnected? yes, The problem is not from cable disconnected. There is a corner case that this function is called at drm shutdown (drm_release). At that time, mainlink is not enabled, hence dp_ctrl_push_idle() will cause system crash. >> + mutex_unlock(&dp_display->event_mutex); >> + return; >> + } >> + >> dp_ctrl_push_idle(dp_display->ctrl); >> + mutex_unlock(&dp_display->event_mutex);