From patchwork Thu Mar 5 20:12:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Paul X-Patchwork-Id: 11422553 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 4CA4492A for ; Thu, 5 Mar 2020 20:13:06 +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 2AF35207FD for ; Thu, 5 Mar 2020 20:13:06 +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="VcvLTlpn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2AF35207FD 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 42E466EC1D; Thu, 5 Mar 2020 20:12:48 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mail-yw1-xc41.google.com (mail-yw1-xc41.google.com [IPv6:2607:f8b0:4864:20::c41]) by gabe.freedesktop.org (Postfix) with ESMTPS id C6E5E6EC1B for ; Thu, 5 Mar 2020 20:12:46 +0000 (UTC) Received: by mail-yw1-xc41.google.com with SMTP id a132so6907206ywb.2 for ; Thu, 05 Mar 2020 12:12:46 -0800 (PST) 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 :mime-version:content-transfer-encoding; bh=7+Fub9X48DBkOVMmN41thr1TsQCekRVfUSS0YxwyrO0=; b=VcvLTlpnPx2BnGfSpZFTnEXI3CAHJQ8Veh8tmqC9bdCCFofi9m2D5I7icPvSPQG+Rc XPWm2wxoHNQ2RkgB43yucdQ9nSzx/ur9aR7OWG5tvF2lN1LXqeHTHL3Uj1AWEyyb1cfW SAqSJUVwq+f7oTDe9HhXuznQ44XJDsm2B3+mXV1lu0gZm0fyhrrGEMevnKoZ9XG5jpHi QoTJsC44YXzjVR9nKc9dMTRMe0qgPOd9a6Uf0fcv0sqN0HtxcAfI7rlK/m6iBk2848o+ sf6BRdICPN9+Te4qkaVdXNFfUERRzgt9eesg7DpqdNHigHS2m+0BOK06f89q9dsSlLF3 XcDA== 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:mime-version:content-transfer-encoding; bh=7+Fub9X48DBkOVMmN41thr1TsQCekRVfUSS0YxwyrO0=; b=F2rxwBPAAF/XExsvVInwsvmjN3M2ASwGBmTYP767JoEM4z96OFpHYItHna/OPl9URt 5uT7WdtbSPhYZCj7KyKw18rNwm3J8JPzxzBZAe7FpllpeuJU0tQRwQOOIM/6vRCK5RCJ 80T02QUJbEyPHtNydrknFqWGwbpKBRnblSP0SAUJA5XGncXFT9FyuvRTr9+DoT520Y2Q 78rw3rdhNKHNV7akzhRb/Zp5mdRq1NWdw0Rd8qpVEpRB/E9tsQEoxpYvKfWcTcztbzQE l5pQHzbq+UdhL+kzD0YFnrYyUt1cnjNh1d6Zm5yWLwqFmekJ16Rksdzkmy+Na85ucsux BEKg== X-Gm-Message-State: ANhLgQ0+V3H4aE8hf8Xt9YjjCgvhUrHCBXRG1D22ft8NnCwyILCUcchZ cCypF1h75NIKkN1z9bO3iL4OR2Ax70o= X-Google-Smtp-Source: ADFU+vv66J58/BA1m4gryIv+mtxDEDrv40Bc1JwWE9UirCz9y4rjYg2GxLwU/+cJIMZ1DfKoTtHDsQ== X-Received: by 2002:a0d:cb95:: with SMTP id n143mr121127ywd.386.1583439165981; Thu, 05 Mar 2020 12:12:45 -0800 (PST) Received: from localhost ([2620:0:1013:11:1e1:4760:6ce4:fc64]) by smtp.gmail.com with ESMTPSA id g65sm12300449ywd.109.2020.03.05.12.12.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Mar 2020 12:12:45 -0800 (PST) From: Sean Paul To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Date: Thu, 5 Mar 2020 15:12:27 -0500 Message-Id: <20200305201236.152307-8-sean@poorly.run> X-Mailer: git-send-email 2.25.1.481.gfbce0eb801-goog In-Reply-To: <20200305201236.152307-1-sean@poorly.run> References: <20200305201236.152307-1-sean@poorly.run> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v5 07/16] 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 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 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 --- 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 dfa792ee90ecd..9523ab6c65e0d 100644 --- a/drivers/gpu/drm/i915/display/intel_hdcp.c +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c @@ -891,8 +891,10 @@ 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 */ @@ -984,6 +986,8 @@ 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) @@ -1862,6 +1866,9 @@ 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,