From patchwork Tue Jun 23 15:58:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Paul X-Patchwork-Id: 11620983 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DAC88618 for ; Tue, 23 Jun 2020 15:59:38 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id B90742073E for ; Tue, 23 Jun 2020 15:59:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=poorly.run header.i=@poorly.run header.b="afmTbRgB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B90742073E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=poorly.run Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D34656E9E0; Tue, 23 Jun 2020 15:59:30 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mail-qv1-xf42.google.com (mail-qv1-xf42.google.com [IPv6:2607:f8b0:4864:20::f42]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5AF2E6E9DE for ; Tue, 23 Jun 2020 15:59:29 +0000 (UTC) Received: by mail-qv1-xf42.google.com with SMTP id d12so9896674qvn.0 for ; Tue, 23 Jun 2020 08:59:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=poorly.run; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=APhYN06XLBrG4CKwWUjPkV1JE/7C2ckvlbk0/Hym88s=; b=afmTbRgBziPD1bZCFBnsqppjwlgitJPseh2NBHK+2x+3WxxGEdQykFn8p/G3uflpy4 JvypAXUvg3N33hzPanZSqXfMTXPL9L2J2khAH5NrVk3vjE10WlOQ5sY40yiF5LVPGsrQ +Fzkm1r/8nnKFGTwfnU9zsQzRgtDazKL+MYsP5b6rXJTvR9LLEs9+xHopuWVVcBW0Isu bWWhfRBdvQON5zI/Grfcikh0v8urK5h+9RQtyYF1jyDL+ng9mxDbs9ZoJAFfsXI/pHSG Dp8Wt7VOUrZDSTB10m5Qf73a0rdnUah/T3TGnMlp6dc2jvBR+/2l6RinDMF+cwjdV2fR pcuQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=APhYN06XLBrG4CKwWUjPkV1JE/7C2ckvlbk0/Hym88s=; b=Bqf0G2fU7SJfJHzkePdlBCIkgD/WDf1kQX68VWdlP3bgWINSgYRY/lp8lRImjd697F IuBUoCX7G5lBaeoit7Tx21KSQeifoov9RstAEFH4x5+iwuLAb/hyrLWNsddjRO1IgXO8 Wvq7ZjxV0efQMZHcyi6nlFmpfSvCOC8tiiPWqSWyblKizoaBOP0H4w9hz37+fXtSnjQ3 HPcCOFSrL2xgaTQyCClvgwpQWmoyKtSwL8TU/95b3oRjeVpNKE3W+31ymJJS4UC1JUL6 pKeggfSbTwVkg4pTAqM+aYmHrZeXIv5oL8Eug+WRHSL9ly85+5qifz9bD4SThL+nVqIr aZvA== X-Gm-Message-State: AOAM533pdPntvGkYe/rqWAkAjOSEgqTwRy/NYdPjtXtEfHFG5Z5eLI6i voYt68xDFmkSO1wbc47fsk0hGA== X-Google-Smtp-Source: ABdhPJxlcrXFFOLfj7UJrIoxN0wS9tHa0tQUVXZHUu5bYdcqPLLu613N0IyJGAIA6sYFEFmA703oLA== X-Received: by 2002:a0c:8168:: with SMTP id 95mr7590131qvc.93.1592927968501; Tue, 23 Jun 2020 08:59:28 -0700 (PDT) Received: from localhost ([166.137.96.174]) by smtp.gmail.com with ESMTPSA id q32sm1038682qte.31.2020.06.23.08.59.27 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Tue, 23 Jun 2020 08:59:28 -0700 (PDT) From: Sean Paul To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Date: Tue, 23 Jun 2020 11:58:57 -0400 Message-Id: <20200623155907.22961-8-sean@poorly.run> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200623155907.22961-1-sean@poorly.run> References: <20200623155907.22961-1-sean@poorly.run> Subject: [Intel-gfx] [PATCH v7 07/17] drm/i915: Protect workers against disappearing connectors X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: daniel.vetter@ffwll.ch, Sean Paul MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" From: Sean Paul This patch adds some protection against connectors being destroyed before the HDCP workers are finished. For check_work, we do a synchronous cancel after the connector is unregistered which will ensure that it is finished before destruction. In the case of prop_work, we can't do a synchronous wait since it needs to take connection_mutex which could cause deadlock. Instead, we'll take a reference on the connector when scheduling prop_work and give it up once we're done. Reviewed-by: Ramalingam C Signed-off-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/20191212190230.188505-8-sean@poorly.run #v2 Link: https://patchwork.freedesktop.org/patch/msgid/20200117193103.156821-8-sean@poorly.run #v3 Link: https://patchwork.freedesktop.org/patch/msgid/20200218220242.107265-8-sean@poorly.run #v4 Link: https://patchwork.freedesktop.org/patch/msgid/20200305201236.152307-8-sean@poorly.run #v5 Link: https://patchwork.freedesktop.org/patch/msgid/20200429195502.39919-8-sean@poorly.run #v6 Changes in v2: -Added to the set Changes in v3: -Change the WARN_ON condition in intel_hdcp_cleanup to allow for initializing connectors as well Changes in v4: -None Changes in v5: -Change WARN_ON to drm_WARN_ON Changes in v6: -None Changes in v7: -None --- drivers/gpu/drm/i915/display/intel_hdcp.c | 44 ++++++++++++++++++++--- 1 file changed, 39 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c index 88500a0bd77e..62cab3aea745 100644 --- a/drivers/gpu/drm/i915/display/intel_hdcp.c +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c @@ -888,8 +888,10 @@ static void intel_hdcp_update_value(struct intel_connector *connector, return; hdcp->value = value; - if (update_property) + if (update_property) { + drm_connector_get(&connector->base); schedule_work(&hdcp->prop_work); + } } /* Implements Part 3 of the HDCP authorization procedure */ @@ -981,6 +983,8 @@ static void intel_hdcp_prop_work(struct work_struct *work) mutex_unlock(&hdcp->mutex); drm_modeset_unlock(&dev_priv->drm.mode_config.connection_mutex); + + drm_connector_put(&connector->base); } bool is_hdcp_supported(struct drm_i915_private *dev_priv, enum port port) @@ -1860,6 +1864,9 @@ static void intel_hdcp_check_work(struct work_struct *work) check_work); struct intel_connector *connector = intel_hdcp_to_connector(hdcp); + if (drm_connector_is_unregistered(&connector->base)) + return; + if (!intel_hdcp2_check_link(connector)) schedule_delayed_work(&hdcp->check_work, DRM_HDCP2_CHECK_PERIOD_MS); @@ -2178,12 +2185,39 @@ void intel_hdcp_component_fini(struct drm_i915_private *dev_priv) void intel_hdcp_cleanup(struct intel_connector *connector) { - if (!connector->hdcp.shim) + struct intel_hdcp *hdcp = &connector->hdcp; + + if (!hdcp->shim) return; - mutex_lock(&connector->hdcp.mutex); - kfree(connector->hdcp.port_data.streams); - mutex_unlock(&connector->hdcp.mutex); + /* + * If the connector is registered, it's possible userspace could kick + * off another HDCP enable, which would re-spawn the workers. + */ + drm_WARN_ON(connector->base.dev, + connector->base.registration_state == DRM_CONNECTOR_REGISTERED); + + /* + * Now that the connector is not registered, check_work won't be run, + * but cancel any outstanding instances of it + */ + cancel_delayed_work_sync(&hdcp->check_work); + + /* + * We don't cancel prop_work in the same way as check_work since it + * requires connection_mutex which could be held while calling this + * function. Instead, we rely on the connector references grabbed before + * scheduling prop_work to ensure the connector is alive when prop_work + * is run. So if we're in the destroy path (which is where this + * function should be called), we're "guaranteed" that prop_work is not + * active (tl;dr This Should Never Happen). + */ + drm_WARN_ON(connector->base.dev, work_pending(&hdcp->prop_work)); + + mutex_lock(&hdcp->mutex); + kfree(hdcp->port_data.streams); + hdcp->shim = NULL; + mutex_unlock(&hdcp->mutex); } void intel_hdcp_atomic_check(struct drm_connector *connector,