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 D40C2C433F5 for ; Fri, 15 Apr 2022 23:10:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356445AbiDOXMp (ORCPT ); Fri, 15 Apr 2022 19:12:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234365AbiDOXMn (ORCPT ); Fri, 15 Apr 2022 19:12:43 -0400 Received: from alexa-out-sd-02.qualcomm.com (alexa-out-sd-02.qualcomm.com [199.106.114.39]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C2D263669B; Fri, 15 Apr 2022 16:10:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1650064212; x=1681600212; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=Qi1FQqfAcjjUuNmVCwF7c0gD3J+aR/jDgdWuepyjcI8=; b=L0OAZFgrmbD9dwUnUuHNJxScR3xKVKH7ddpJw3kubvKlliIHL9Mwh4Qo z7z4Cwwyzt0TQBcfC9igrWySd/NUP2X6gsDfehgMaeTT282Mqzfnb8/nI 42mDdvFCCVJbolMhdGhelpIThXaqfppJ/Z98rOQjenOqGiI52E+jlXSLh Y=; Received: from unknown (HELO ironmsg02-sd.qualcomm.com) ([10.53.140.142]) by alexa-out-sd-02.qualcomm.com with ESMTP; 15 Apr 2022 16:10:12 -0700 X-QCInternal: smtphost Received: from nasanex01c.na.qualcomm.com ([10.47.97.222]) by ironmsg02-sd.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Apr 2022 16:10:12 -0700 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; Fri, 15 Apr 2022 16:10:11 -0700 Received: from [10.110.19.13] (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; Fri, 15 Apr 2022 16:10:10 -0700 Message-ID: Date: Fri, 15 Apr 2022 16:10:09 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH v7] drm/msm/dp: stop event kernel thread when DP unbind Content-Language: en-US To: Dmitry Baryshkov CC: , , , , , , , , , , , , , , References: <1650062064-11838-1-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: 8bit 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) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/15/2022 3:48 PM, Dmitry Baryshkov wrote: > On Sat, 16 Apr 2022 at 01:34, Kuogee Hsieh wrote: >> Current DP driver implementation, event thread is kept running >> after DP display is unbind. This patch fix this problem by disabling >> DP irq and stop event thread to exit gracefully at dp_display_unbind(). >> >> Changes in v2: >> -- start event thread at dp_display_bind() >> >> Changes in v3: >> -- disable all HDP interrupts at unbind >> -- replace dp_hpd_event_setup() with dp_hpd_event_thread_start() >> -- replace dp_hpd_event_stop() with dp_hpd_event_thread_stop() >> -- move init_waitqueue_head(&dp->event_q) to probe() >> -- move spin_lock_init(&dp->event_lock) to probe() >> >> Changes in v4: >> -- relocate both dp_display_bind() and dp_display_unbind() to bottom of file >> >> Changes in v5: >> -- cancel relocation of both dp_display_bind() and dp_display_unbind() >> >> Changes in v6: >> -- move empty event q to dp_event_thread_start() >> >> Changes in v7: >> -- call ktheread_stop() directly instead of dp_hpd_event_thread_stop() function >> >> Fixes: e91e3065a806 ("drm/msm/dp: Add DP compliance tests on Snapdragon Chipsets") >> Signed-off-by: Kuogee Hsieh >> Reported-by: Dmitry Baryshkov >> Reviewed-by: Stephen Boyd >> --- >> drivers/gpu/drm/msm/dp/dp_display.c | 31 ++++++++++++++++++++++++------- >> 1 file changed, 24 insertions(+), 7 deletions(-) >> >> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c >> index 01453db..680e500 100644 >> --- a/drivers/gpu/drm/msm/dp/dp_display.c >> +++ b/drivers/gpu/drm/msm/dp/dp_display.c >> @@ -113,6 +113,7 @@ struct dp_display_private { >> u32 hpd_state; >> u32 event_pndx; >> u32 event_gndx; >> + struct task_struct *ev_tsk; >> struct dp_event event_list[DP_EVENT_Q_MAX]; >> spinlock_t event_lock; >> >> @@ -230,6 +231,8 @@ void dp_display_signal_audio_complete(struct msm_dp *dp_display) >> complete_all(&dp->audio_comp); >> } >> >> +static int dp_hpd_event_thread_start(struct dp_display_private *dp_priv); >> + >> static int dp_display_bind(struct device *dev, struct device *master, >> void *data) >> { >> @@ -269,6 +272,7 @@ static int dp_display_bind(struct device *dev, struct device *master, >> if (rc) >> DRM_ERROR("Audio registration Dp failed\n"); > I think I asked it in v3 and didn't get an answer: > Isn't 'goto end' missing here? I did follow you suggestion at v3 and made changes at dp_hpd_event_thread_start() >> + rc = dp_hpd_event_thread_start(dp); > if (rc) { DRM_ERROR(....); goto end; } > return 0; > > Please. This is at dp_display_bind(),  "end" is the next statement why goto needed? >> end: >> return rc; >> } >> @@ -280,6 +284,11 @@ static void dp_display_unbind(struct device *dev, struct device *master, >> struct drm_device *drm = dev_get_drvdata(master); >> struct msm_drm_private *priv = drm->dev_private; >> >> + /* disable all HPD interrupts */ >> + dp_catalog_hpd_config_intr(dp->catalog, DP_DP_HPD_INT_MASK, false); >> + >> + kthread_stop(dp->ev_tsk); >> + >> dp_power_client_deinit(dp->power); >> dp_aux_unregister(dp->aux); >> priv->dp[dp->id] = NULL; >> @@ -1054,7 +1063,7 @@ static int hpd_event_thread(void *data) >> >> dp_priv = (struct dp_display_private *)data; >> >> - while (1) { >> + while (!kthread_should_stop()) { >> if (timeout_mode) { >> wait_event_timeout(dp_priv->event_q, >> (dp_priv->event_pndx == dp_priv->event_gndx), >> @@ -1132,12 +1141,19 @@ static int hpd_event_thread(void *data) >> return 0; >> } >> >> -static void dp_hpd_event_setup(struct dp_display_private *dp_priv) >> +static int dp_hpd_event_thread_start(struct dp_display_private *dp_priv) >> { >> - init_waitqueue_head(&dp_priv->event_q); >> - spin_lock_init(&dp_priv->event_lock); >> + /* set event q to empty */ >> + dp_priv->event_gndx = 0; >> + dp_priv->event_pndx = 0; >> + >> + dp_priv->ev_tsk = kthread_run(hpd_event_thread, dp_priv, "dp_hpd_handler"); >> + if (IS_ERR(dp_priv->ev_tsk)) { >> + DRM_ERROR("failed to create DP event thread\n"); >> + return PTR_ERR(dp_priv->ev_tsk); >> + } >> >> - kthread_run(hpd_event_thread, dp_priv, "dp_hpd_handler"); >> + return 0; >> } >> >> static irqreturn_t dp_display_irq_handler(int irq, void *dev_id) >> @@ -1266,7 +1282,10 @@ static int dp_display_probe(struct platform_device *pdev) >> return -EPROBE_DEFER; >> } >> >> + /* setup event q */ >> mutex_init(&dp->event_mutex); >> + init_waitqueue_head(&dp->event_q); >> + spin_lock_init(&dp->event_lock); >> >> /* Store DP audio handle inside DP display */ >> dp->dp_display.dp_audio = dp->audio; >> @@ -1441,8 +1460,6 @@ void msm_dp_irq_postinstall(struct msm_dp *dp_display) >> >> dp = container_of(dp_display, struct dp_display_private, dp_display); >> >> - dp_hpd_event_setup(dp); >> - >> dp_add_event(dp, EV_HPD_INIT_SETUP, 0, 100); >> } >> >> -- >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, >> a Linux Foundation Collaborative Project >> >