From patchwork Fri Oct 7 16:00:47 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Philipp Zabel X-Patchwork-Id: 9366479 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id CF4C760752 for ; Fri, 7 Oct 2016 16:01:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C10772973F for ; Fri, 7 Oct 2016 16:01:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B5DA529743; Fri, 7 Oct 2016 16:01:18 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4E1312973F for ; Fri, 7 Oct 2016 16:01:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936176AbcJGQBP (ORCPT ); Fri, 7 Oct 2016 12:01:15 -0400 Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:36439 "EHLO metis.ext.4.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933508AbcJGQBN (ORCPT ); Fri, 7 Oct 2016 12:01:13 -0400 Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7] helo=dude.pengutronix.de.) by metis.ext.pengutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1bsXaB-0002OS-MX; Fri, 07 Oct 2016 18:01:11 +0200 From: Philipp Zabel To: linux-media@vger.kernel.org Cc: Steve Longerbeam , Marek Vasut , Hans Verkuil , kernel@pengutronix.de, Philipp Zabel Subject: [PATCH 02/22] [media] v4l2-async: allow subdevices to add further subdevices to the notifier waiting list Date: Fri, 7 Oct 2016 18:00:47 +0200 Message-Id: <20161007160107.5074-3-p.zabel@pengutronix.de> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20161007160107.5074-1-p.zabel@pengutronix.de> References: <20161007160107.5074-1-p.zabel@pengutronix.de> X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: p.zabel@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-media@vger.kernel.org Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently the v4l2_async_notifier needs to be given a list of matches for all expected subdevices on creation. When chaining subdevices that are asynchronously probed via device tree, the bridge device that sets up the notifier does not know the complete list of subdevices, as it can only parse its own device tree node to obtain information about the nearest neighbor subdevices. To support indirectly connected subdevices, we need to support amending the existing notifier waiting list with newly found neighbor subdevices with each registered subdevice. This can be achieved by adding new v42l_async_subdev matches to the notifier waiting list during the v4l2_subdev registered callback, which is called under the list lock from either v4l2_async_register_subdev or v4l2_async_notifier_register. For this purpose a new exported function __v4l2_async_notifier_add_subdev is added. Signed-off-by: Philipp Zabel --- drivers/media/v4l2-core/v4l2-async.c | 78 ++++++++++++++++++++++++++++++++++-- include/media/v4l2-async.h | 12 ++++++ 2 files changed, 86 insertions(+), 4 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c index c4f1930..404eeea 100644 --- a/drivers/media/v4l2-core/v4l2-async.c +++ b/drivers/media/v4l2-core/v4l2-async.c @@ -109,6 +109,7 @@ static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier, if (ret < 0) return ret; } + /* Move from the global subdevice list to notifier's done */ list_move(&sd->async_list, ¬ifier->done); @@ -158,7 +159,7 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev, struct v4l2_async_notifier *notifier) { struct v4l2_async_subdev *asd; - int ret; + struct list_head *tail; int i; if (!notifier->num_subdevs || notifier->num_subdevs > V4L2_MAX_SUBDEVS) @@ -191,17 +192,71 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev, /* Keep also completed notifiers on the list */ list_add(¬ifier->list, ¬ifier_list); + do { + int ret; + + tail = notifier->waiting.prev; + + ret = v4l2_async_test_notify_all(notifier); + if (ret < 0) { + mutex_unlock(&list_lock); + return ret; + } + + /* + * If entries were added to the notifier waiting list, check + * again if the corresponding subdevices are already available. + */ + } while (tail != notifier->waiting.prev); + mutex_unlock(&list_lock); - return ret; + return 0; } EXPORT_SYMBOL(v4l2_async_notifier_register); +int __v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier, + struct v4l2_async_subdev *asd) +{ + struct v4l2_async_subdev *tmp_asd; + + lockdep_assert_held(&list_lock); + + if (asd->match_type != V4L2_ASYNC_MATCH_OF) + return -EINVAL; + + /* + * First check if the same notifier is already on the waiting or done + * lists. This can happen if a subdevice with multiple outputs is added + * by all its downstream subdevices. + */ + list_for_each_entry(tmp_asd, ¬ifier->waiting, list) + if (tmp_asd->match.of.node == asd->match.of.node) + return 0; + list_for_each_entry(tmp_asd, ¬ifier->done, list) + if (tmp_asd->match.of.node == asd->match.of.node) + return 0; + + /* + * Add the new async subdev to the notifier waiting list, so + * v4l2_async_belongs may use it to compare against entries in + * subdev_list. + * In case the subdev matching asd has already been passed in the + * subdev_list walk in v4l2_async_notifier_register, or if + * we are called from v4l2_async_register_subdev, the subdev_list + * will have to be walked again. + */ + list_add_tail(&asd->list, ¬ifier->waiting); + + return 0; +} + void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier) { struct v4l2_subdev *sd, *tmp; - unsigned int notif_n_subdev = notifier->num_subdevs; - unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS); + unsigned int notif_n_subdev = 0; + unsigned int n_subdev; + struct list_head *list; struct device **dev; int i = 0; @@ -218,6 +273,10 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier) list_del(¬ifier->list); + list_for_each(list, ¬ifier->done) + ++notif_n_subdev; + n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS); + list_for_each_entry_safe(sd, tmp, ¬ifier->done, async_list) { struct device *d; @@ -294,8 +353,19 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd) list_for_each_entry(notifier, ¬ifier_list, list) { struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, sd); if (asd) { + struct list_head *tail = notifier->waiting.prev; int ret = v4l2_async_test_notify(notifier, sd, asd); + + /* + * If entries were added to the notifier waiting list, + * check if the corresponding subdevices are already + * available. + */ + if (tail != notifier->waiting.prev) + ret = v4l2_async_test_notify_all(notifier); + mutex_unlock(&list_lock); + return ret; } } diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h index 8e2a236..e4e4b11 100644 --- a/include/media/v4l2-async.h +++ b/include/media/v4l2-async.h @@ -114,6 +114,18 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev, struct v4l2_async_notifier *notifier); /** + * __v4l2_async_notifier_add_subdev - adds a subdevice to the notifier waitlist + * + * @v4l2_notifier: notifier the calling subdev is bound to + * @asd: asynchronous subdev match + * + * To be called from inside a subdevices' registered_async callback to add + * additional subdevices to the notifier waiting list. + */ +int __v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier, + struct v4l2_async_subdev *asd); + +/** * v4l2_async_notifier_unregister - unregisters a subdevice asynchronous notifier * * @notifier: pointer to &struct v4l2_async_notifier