From patchwork Thu Apr 7 16:51:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuogee Hsieh X-Patchwork-Id: 12805535 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 04260C433F5 for ; Thu, 7 Apr 2022 16:51:38 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DD20F10EBC1; Thu, 7 Apr 2022 16:51:37 +0000 (UTC) Received: from alexa-out.qualcomm.com (alexa-out.qualcomm.com [129.46.98.28]) by gabe.freedesktop.org (Postfix) with ESMTPS id 69F0E10EBBF; Thu, 7 Apr 2022 16:51:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1649350296; x=1680886296; h=from:to:cc:subject:date:message-id:mime-version; bh=zWgHs9WoOcSa0eb+PT/FFhzIfcD017bTdrABzx78AoA=; b=bwIbaRiWgEVkI7Gm6mPJOcZHJNHk0XhA6GTYcL+b6F1udMMGjECh4q5C yG3sqiRiVp0qpAK2lioLOOHx8Jw+loEaDcekXyKOFzjo4K0BVlzBKxs2s 84OhyOYgN2ElxggBvIJK6rBcINzTuGwVLmM3wiwzJRk2evBxZtQhnBa+V g=; Received: from ironmsg-lv-alpha.qualcomm.com ([10.47.202.13]) by alexa-out.qualcomm.com with ESMTP; 07 Apr 2022 09:51:35 -0700 X-QCInternal: smtphost Received: from nasanex01c.na.qualcomm.com ([10.47.97.222]) by ironmsg-lv-alpha.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Apr 2022 09:51:35 -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; Thu, 7 Apr 2022 09:51:34 -0700 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 15.2.986.22; Thu, 7 Apr 2022 09:51:34 -0700 From: Kuogee Hsieh To: , , , , , , , , Subject: [PATCH] drm/msm/dp: add fail safe mode outside of event_mutex context Date: Thu, 7 Apr 2022 09:51:26 -0700 Message-ID: <1649350286-11504-1-git-send-email-quic_khsieh@quicinc.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01a.na.qualcomm.com (10.47.209.196) X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: quic_sbillaka@quicinc.com, linux-arm-msm@vger.kernel.org, quic_abhinavk@quicinc.com, dri-devel@lists.freedesktop.org, quic_khsieh@quicinc.com, quic_aravindh@quicinc.com, freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" There is possible circular locking dependency detected on event_mutex. To break this possible circular locking, this patch move setting fail safe mode out of event_mutex scope. Fixes: d4aca422539c ("drm/msm/dp: always add fail-safe mode into connector mode list") Signed-off-by: Kuogee Hsieh --- drivers/gpu/drm/msm/dp/dp_display.c | 6 ++++++ drivers/gpu/drm/msm/dp/dp_panel.c | 20 ++++++++++---------- drivers/gpu/drm/msm/dp/dp_panel.h | 1 + 3 files changed, 17 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c index 178b774..a42732b 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -580,6 +580,12 @@ static int dp_hpd_plug_handle(struct dp_display_private *dp, u32 data) dp->dp_display.connector_type, state); mutex_unlock(&dp->event_mutex); + /* + * add fail safe mode outside event_mutex scope + * to avoid potiential circular lock with drm thread + */ + dp_panel_add_fail_safe_mode(dp->dp_display.connector); + /* uevent will complete connection part */ return 0; }; diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c index f141872..26c3653 100644 --- a/drivers/gpu/drm/msm/dp/dp_panel.c +++ b/drivers/gpu/drm/msm/dp/dp_panel.c @@ -151,6 +151,15 @@ static int dp_panel_update_modes(struct drm_connector *connector, return rc; } +void dp_panel_add_fail_safe_mode(struct drm_connector *connector) +{ + /* fail safe edid */ + mutex_lock(&connector->dev->mode_config.mutex); + if (drm_add_modes_noedid(connector, 640, 480)) + drm_set_preferred_mode(connector, 640, 480); + mutex_unlock(&connector->dev->mode_config.mutex); +} + int dp_panel_read_sink_caps(struct dp_panel *dp_panel, struct drm_connector *connector) { @@ -207,16 +216,7 @@ int dp_panel_read_sink_caps(struct dp_panel *dp_panel, goto end; } - /* fail safe edid */ - mutex_lock(&connector->dev->mode_config.mutex); - if (drm_add_modes_noedid(connector, 640, 480)) - drm_set_preferred_mode(connector, 640, 480); - mutex_unlock(&connector->dev->mode_config.mutex); - } else { - /* always add fail-safe mode as backup mode */ - mutex_lock(&connector->dev->mode_config.mutex); - drm_add_modes_noedid(connector, 640, 480); - mutex_unlock(&connector->dev->mode_config.mutex); + dp_panel_add_fail_safe_mode(connector); } if (panel->aux_cfg_update_done) { diff --git a/drivers/gpu/drm/msm/dp/dp_panel.h b/drivers/gpu/drm/msm/dp/dp_panel.h index 9023e5b..99739ea 100644 --- a/drivers/gpu/drm/msm/dp/dp_panel.h +++ b/drivers/gpu/drm/msm/dp/dp_panel.h @@ -59,6 +59,7 @@ int dp_panel_init_panel_info(struct dp_panel *dp_panel); int dp_panel_deinit(struct dp_panel *dp_panel); int dp_panel_timing_cfg(struct dp_panel *dp_panel); void dp_panel_dump_regs(struct dp_panel *dp_panel); +void dp_panel_add_fail_safe_mode(struct drm_connector *connector); int dp_panel_read_sink_caps(struct dp_panel *dp_panel, struct drm_connector *connector); u32 dp_panel_get_mode_bpp(struct dp_panel *dp_panel, u32 mode_max_bpp,