From patchwork Mon Dec 28 18:05:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ezequiel Garcia X-Patchwork-Id: 11991595 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C30EFC433E0 for ; Mon, 28 Dec 2020 18:06:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 81E09229EF for ; Mon, 28 Dec 2020 18:06:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728891AbgL1SGI (ORCPT ); Mon, 28 Dec 2020 13:06:08 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:60478 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728889AbgL1SGH (ORCPT ); Mon, 28 Dec 2020 13:06:07 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: ezequiel) with ESMTPSA id 8FA6C1F44107 From: Ezequiel Garcia To: linux-media@vger.kernel.org, Hans Verkuil Cc: kernel@collabora.com, Laurent Pinchart , Sakari Ailus , Ezequiel Garcia Subject: [PATCH] media: v4l2-async: Add waiting subdevices debugfs Date: Mon, 28 Dec 2020 15:05:11 -0300 Message-Id: <20201228180511.43486-1-ezequiel@collabora.com> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org There is currently little to none information available about the reasons why a v4l2-async device hasn't probed completely. Inspired by the "devices_deferred" debugfs file, add a file to list information about the subdevices that are on waiting lists, for each notifier. This is useful to debug v4l2-async subdevices and notifiers, for instance when doing device bring-up. For instance, a typical output would be: $ cat /sys/kernel/debug/video4linux/waiting_subdevices [fwnode] 1-003c [fwnode] 20e0000.iomuxc-gpr:ipu1_csi1_mux [fwnode] 20e0000.iomuxc-gpr:ipu1_csi0_mux It's possible to provide some more information, detecting the type of fwnode and printing of-specific or acpi-specific details. For now, the implementation is kept simple. Also, note that match-type "custom" prints no information. Since there are no in-tree users of this match-type, the implementation doesn't bother. Signed-off-by: Ezequiel Garcia Reported-by: kernel test robot --- drivers/media/v4l2-core/v4l2-async.c | 54 ++++++++++++++++++++++++++++ drivers/media/v4l2-core/v4l2-dev.c | 5 +++ include/media/v4l2-async.h | 7 ++++ 3 files changed, 66 insertions(+) diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c index e3ab003a6c85..32cd1ecced97 100644 --- a/drivers/media/v4l2-core/v4l2-async.c +++ b/drivers/media/v4l2-core/v4l2-async.c @@ -5,6 +5,7 @@ * Copyright (C) 2012-2013, Guennadi Liakhovetski */ +#include #include #include #include @@ -14,6 +15,7 @@ #include #include #include +#include #include #include @@ -837,3 +839,55 @@ void v4l2_async_unregister_subdev(struct v4l2_subdev *sd) mutex_unlock(&list_lock); } EXPORT_SYMBOL(v4l2_async_unregister_subdev); + +static void print_waiting_subdev(struct seq_file *s, + struct v4l2_async_subdev *asd) +{ + switch (asd->match_type) { + case V4L2_ASYNC_MATCH_CUSTOM: + seq_puts(s, "[custom]\n"); + break; + case V4L2_ASYNC_MATCH_DEVNAME: + seq_printf(s, "[devname] %s\n", + asd->match.device_name); + break; + case V4L2_ASYNC_MATCH_I2C: + seq_printf(s, "[i2c] %d-%04x\n", + asd->match.i2c.adapter_id, + asd->match.i2c.address); + break; + case V4L2_ASYNC_MATCH_FWNODE: { + struct fwnode_handle *fwnode = asd->match.fwnode; + + if (fwnode_graph_is_endpoint(fwnode)) + fwnode = fwnode_graph_get_port_parent(fwnode); + + seq_printf(s, "[fwnode] %s\n", + fwnode->dev ? dev_name(fwnode->dev) : "nil"); + break; + } + } +} + +static int waiting_subdevs_show(struct seq_file *s, void *data) +{ + struct v4l2_async_notifier *notifier; + struct v4l2_async_subdev *asd; + + mutex_lock(&list_lock); + + list_for_each_entry(notifier, ¬ifier_list, list) + list_for_each_entry(asd, ¬ifier->waiting, list) + print_waiting_subdev(s, asd); + + mutex_unlock(&list_lock); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(waiting_subdevs); + +void v4l2_async_debug_init(struct dentry *debugfs_dir) +{ + debugfs_create_file("waiting_subdevices", 0444, debugfs_dir, NULL, + &waiting_subdevs_fops); +} diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c index a593ea0598b5..8d3813e6ab56 100644 --- a/drivers/media/v4l2-core/v4l2-dev.c +++ b/drivers/media/v4l2-core/v4l2-dev.c @@ -14,6 +14,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include #include #include #include @@ -37,6 +38,7 @@ __func__, ##arg); \ } while (0) +static struct dentry *v4l2_debugfs_dir; /* * sysfs stuff @@ -1113,6 +1115,8 @@ static int __init videodev_init(void) return -EIO; } + v4l2_debugfs_dir = debugfs_create_dir("video4linux", NULL); + v4l2_async_debug_init(v4l2_debugfs_dir); return 0; } @@ -1120,6 +1124,7 @@ static void __exit videodev_exit(void) { dev_t dev = MKDEV(VIDEO_MAJOR, 0); + debugfs_remove_recursive(v4l2_debugfs_dir); class_unregister(&video_class); unregister_chrdev_region(dev, VIDEO_NUM_DEVICES); } diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h index d6e31234826f..312ab421aa40 100644 --- a/include/media/v4l2-async.h +++ b/include/media/v4l2-async.h @@ -137,6 +137,13 @@ struct v4l2_async_notifier { struct list_head list; }; +/** + * v4l2_async_debug_init - Initialize debugging tools. + * + * @debugfs_dir: pointer to the parent debugfs &struct dentry + */ +void v4l2_async_debug_init(struct dentry *debugfs_dir); + /** * v4l2_async_notifier_init - Initialize a notifier. *