From patchwork Thu Jul 16 01:01:20 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 496125 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id E60381401E7; Thu, 16 Jul 2015 11:05:34 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1ZFXcA-00053s-QI; Thu, 16 Jul 2015 01:05:30 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1ZFXYB-0002qo-4x for kernel-team@lists.ubuntu.com; Thu, 16 Jul 2015 01:01:23 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1ZFXYA-0006Ci-QR; Thu, 16 Jul 2015 01:01:22 +0000 Received: from kamal by fourier with local (Exim 4.82) (envelope-from ) id 1ZFXY8-0000x9-Jf; Wed, 15 Jul 2015 18:01:20 -0700 From: Kamal Mostafa To: Daniel Vetter Subject: [3.19.y-ckt stable] Patch "drm/dp/mst: make sure mst_primary mstb is valid in work function" has been added to staging queue Date: Wed, 15 Jul 2015 18:01:20 -0700 Message-Id: <1437008480-3633-1-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 X-Extended-Stable: 3.19 Cc: Daniel Vetter , Kamal Mostafa , kernel-team@lists.ubuntu.com, Dave Airlie X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled drm/dp/mst: make sure mst_primary mstb is valid in work function to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue This patch is scheduled to be released in version 3.19.y-ckt4. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.19.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 4bec1c3c44a859779e1cd7bc582c7718b983fae0 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Mon, 22 Jun 2015 17:31:59 +1000 Subject: drm/dp/mst: make sure mst_primary mstb is valid in work function commit 9254ec496a1dbdddeab50021a8138dc627a8166a upstream. This validates the mst_primary under the lock, and then calls into the check and send function. This makes the code a lot easier to understand the locking rules in. Signed-off-by: Daniel Vetter Reviewed-by: Daniel Vetter Signed-off-by: Dave Airlie Signed-off-by: Kamal Mostafa --- drivers/gpu/drm/drm_dp_mst_topology.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) -- 1.9.1 diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 9a5b687..e0da405 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1185,7 +1185,7 @@ static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *m struct drm_dp_mst_branch *mstb) { struct drm_dp_mst_port *port; - + struct drm_dp_mst_branch *mstb_child; if (!mstb->link_address_sent) { drm_dp_send_link_address(mgr, mstb); mstb->link_address_sent = true; @@ -1200,17 +1200,31 @@ static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *m if (!port->available_pbn) drm_dp_send_enum_path_resources(mgr, mstb, port); - if (port->mstb) - drm_dp_check_and_send_link_address(mgr, port->mstb); + if (port->mstb) { + mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb); + if (mstb_child) { + drm_dp_check_and_send_link_address(mgr, mstb_child); + drm_dp_put_mst_branch_device(mstb_child); + } + } } } static void drm_dp_mst_link_probe_work(struct work_struct *work) { struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work); + struct drm_dp_mst_branch *mstb; - drm_dp_check_and_send_link_address(mgr, mgr->mst_primary); - + mutex_lock(&mgr->lock); + mstb = mgr->mst_primary; + if (mstb) { + kref_get(&mstb->kref); + } + mutex_unlock(&mgr->lock); + if (mstb) { + drm_dp_check_and_send_link_address(mgr, mstb); + drm_dp_put_mst_branch_device(mstb); + } } static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,